bromochloroacetic-acid and Soft-Tissue-Neoplasms

In the past decade, several emerging bone and soft tissue neoplasms of the head and neck region have been described in the literature, including GLI1-altered mesenchymal tumors, (intraosseous) rhabdomyosarcoma with TFCP2 fusion, and adamantinoma-like Ewing sarcoma. This review provides a summary of the clinical features, histologic characteristics, immunoprofile, key diagnostic features, and differential diagnoses of these emerging entities. Notably, all three entities show epithelioid morphology and cytokeratin immunopositivity, highlighting the need to consider these mesenchymal neoplasms in the differential diagnoses of cytokeratin-positive epithelioid tumors in the head and neck region. Appropriate workups including detection of the characteristic molecular alterations are essential for the correct diagnosis.

Topics: Biomarkers, Tumor; Bone Neoplasms; DNA-Binding Proteins; Head and Neck Neoplasms; Humans; Keratins; Los Angeles; Sarcoma, Ewing; Soft Tissue Neoplasms; Transcription Factors

Leiomyosarcoma represents a rather uncommon malignancy, and reports of cases characterized by a renal genesis are particularly rare.. We describe 2 cases of leiomyosarcoma of the kidney, in a 63-year-old woman and in a 53-year-old man, respectively. Both tumors share a common immunohistochemical profile with a strong positivity for smooth muscle actin, a focal positivity for desmin, and negativity for cytokeratins and other markers.. We provide a comparison between our findings and the data available in the literature, and we note an interesting relatively long survival in our patients (10 months for the first case and 20 months for the second case).

Topics: Female; Humans; Immunohistochemistry; Keratins; Kidney Neoplasms; Leiomyosarcoma; Male; Middle Aged; Soft Tissue Neoplasms

Parachordoma is an extremely uncommon soft-tissue tumor, which mainly occurs in the deep soft-tissue of the distal parts of the limbs, such as deep fascia, muscle tendon, synovial or soft-tissue closed to the bone. Nevertheless, the literature reports about parachordoma on the thoracic wall were scarce. The clinical and imaging manifestation has a non-specific appearance. In this article, we reported one case of parachordoma of the thoracic wall that we met in clinical works and reviewed the literature.

Topics: Adult; Bone Neoplasms; Humans; Keratins; Male; Radiography; Ribs; S100 Proteins; Soft Tissue Neoplasms; Vimentin

Parachordoma is a very rare peripheral soft tissue tumor of unknown lineage, which has been described under other names, all of which imply a similarity to chordoma. It forms a circumscribed firm tumor, usually in deep soft tissue, with a variety of histologic patterns and cytologic features, including cords and nests of cells, some of which are vacuolated. The ultrastructure and immunophenotype indicate epithelial differentiation and parachordomas are additionally S-100 protein positive. This tumor is distinct from extraskeletal myxoid chondrosarcoma and probably from soft tissue myoepithelioma. While histologically it somewhat resembles chordoma, parachordoma has a wider range of appearances, and the two neoplasms differ in their detailed cytokeratin immunophenotype and their clinical behavior. Parachordoma is a slowly growing tumor with occasional late recurrence; cases with reported metastasis have not been histologically convincing. This commentary discusses the terminology, origin, and possible nature of this enigmatic neoplasm.

Topics: Adolescent; Adult; Arm; Buttocks; Child; Chondroma; Collagen; Fascia; Female; Humans; Immunohistochemistry; Keratins; Male; Middle Aged; Monosomy; S100 Proteins; Soft Tissue Neoplasms; Thigh; Thorax; Trisomy

The tumor designated by Stout and Murray as "hemangiopericytoma" (HPC) more than 50 years ago continues to represent a source of uncertainty and disagreement among pathologists. In particular, questions exist regarding the synonymity of a hemangiopericytomatous growth pattern--defined by a monomorphic population of compact polygonal or bluntly fusiform cells and a branching stromal vascular pattern with a "staghorn" configuration--and the presence of a reproducible biological entity. It has been shown repeatedly that these same histologic features may be observed at least focally in a diversity of neoplasms, including "true" hemangiopericytomas, synovial sarcomas, mesenchymal chondrosarcomas, infantile fibrosarcomas, malignant fibrous histiocytomas, malignant peripheral nerve sheath tumors, leiomyosarcomas, endometrial stromal sarcomas, solitary fibrous tumors, myofibromas, malignant mesotheliomas, thymomas, sarcomatoid carcinomas, malignant melanomas, and "phosphaturic mesenchymal tumors." Despite their potential sharing of the microscopic attributes in question, such neoplasms have individualistic clinical features and can also be distinguished from one another by specialized pathologic analyses. HPC is "defined" in that context by reactivity for vimentin, with or without CD34 and CD57, but it lacks other immunodeterminants of epithelial, neural, and myogenous differentiation. Paradoxically, this phenotype is indeed associated with the presence of myogenous-type cytoplasmic filaments in ultrastructural evaluations of HPC. Other lesions that may resemble "true" HPC--but which possess dissimilar subcellular and clinical characteristics--include solitary fibrous tumors, hemangiopericytomalike tumors of the sinonasal tract, and "infantile (congenital) hemangiopericytomas." Such observations suggest that the hemangiopericytoma is both a pathologic entity and a morphological pattern, and they emphasize the utility of adjuvant pathologic studies in this diagnostic context.

Topics: Actins; Bone Neoplasms; CD57 Antigens; Diagnosis, Differential; Hemangiopericytoma; Humans; Keratins; Meningioma; Myofibromatosis; Nasopharyngeal Neoplasms; Reticulin; Sarcoma, Synovial; Soft Tissue Neoplasms; Stromal Cells

Since the concept of malignant fibrous histiocytoma (MFH) was introduced and subsequently popularized in the 1960's and 1970's, it has become widely regarded as the commonest soft-tissue sarcoma of adulthood. Although the initial notion that MFH was a true histiocytic tumor showing faculative fibroblastic differentiation has been disproved, and despite the lack of definable, reproducible diagnostic criteria and considerable immunophenotypic, ultrastructural and karyotypic heterogeneity, MFH is still accepted widely as a discrete clinicopathologic entity. On the other hand several recent studies have expressed considerable doubts about MFH, or at least pleomorphic MFH, as an "entity" and have suggested that it represents a common morphologic manifestation of a host of poorly differentiated sarcomas and, more rarely, other neoplasms. This article reviews the clinicopathologic features of MFH and its established variants in the context of this debate and considers the evidence for and against their continued acceptance as distinct entities or as a cohesive group. We conclude that the pleomorphic, giant cell and inflammatory variants each represent heterogeneous diagnostic groups which are hard to defend as cohesive entities, while the myxoid ("myxofibrosarcoma") and angiomatoid types are distinct, reproducible tumor types.

Topics: Desmin; Fibrosarcoma; Giant Cell Tumors; Histiocytoma, Benign Fibrous; Humans; Keratins; Leiomyosarcoma; Retroperitoneal Neoplasms; Soft Tissue Neoplasms

We report a case of parachordoma occurring in the buttock of a 43-year-old man, and review 20 cases of parachordoma reported in the English literature. The tumor in our case was grossly 3 cm in dimension, solid, lobulated and grayish-white in color. Microscopically, the tumor consisted of epithelioid and spindle cells, and fibromyxoid stroma. The epithelioid cells were immunohistochemically positive for vimentin, S-100 protein, neuron-specific enolase, keratin, carcinoembryonic antigen and epithelial membrane antigen, and negative for HMB45. These findings are similar to those for chordoma rather than extraskeletal myxoid chrondrosarcoma. Although the etiopathogenesis of parachordoma remains obscure, Schwann cells or some other neuron-related cell origin are suspected.

Topics: Adult; Buttocks; Carcinoembryonic Antigen; Chondrosarcoma; Chordoma; Diagnosis, Differential; Humans; Immunohistochemistry; Keratins; Male; S100 Proteins; Soft Tissue Neoplasms

It has been established that nonrandom chromosome rearrangements are characteristic of specific types of neoplasia. We present six new cases of sarcoma that had in common the same chromosome abnormality, i.e., a balanced translocation between chromosomes X and 18, t(X;18)(p11.2;q11.2), and evaluate the 15 cases with this translocation in the literature. The histological diagnosis was synovial sarcoma in 19 cases and malignant fibrous histiocytoma and fibrosarcoma in the remaining two tumors, respectively. The translocation was found in tumors of both the biphasic and monophasic types, as well as in poorly differentiated synovial sarcoma. The two nonsynovial sarcomas with the t(X;18) were described as spindle cell tumors but failed to show the presence of cytokeratins by immunohistochemical stains. Even with the numerous variabilities on which this test depends, the cytogenetic analysis holds great promise as a tool for the diagnosis of synovial sarcoma.

Topics: Adult; Chromosomes, Human, Pair 18; Female; Humans; Keratins; Male; Middle Aged; Neoplasm Proteins; Sarcoma, Synovial; Soft Tissue Neoplasms; Translocation, Genetic; X Chromosome

Historically, antibodies to cytokeratin intermediate filaments have been models of target specificity. In most diagnostic settings, the utility of these antibodies was unquestioned; reactivity for cytokeratin was dogmatically equated with epithelial differentiation. Recently, however, the diagnostic importance of these antibodies has been challenged, prompted by the demonstration of cytokeratin reactivity in a variety of "nonepithelial" neoplasms. In this review, the evolving literature on this topic is explored, and the practical implications of these findings are discussed.

Topics: Humans; Keratins; Sarcoma; Soft Tissue Neoplasms

A case of paravertebral malignant rhabdoid tumor in a 59-year-old man is described. The location of the tumor and age of the patient appear to be unique. The clinical evolution was aggressive and resulted in the death of the patient. The tumor exhibited the light microscopic features of a typical rhabdoid tumor. It was composed of poorly differentiated round or polygonal cells with acidophilic glassy inclusions and vesicular nuclei exhibiting prominent nucleoli. Immunohistochemistry revealed the coexpression of cytokeratin and vimentin in neoplastic cells.

Topics: Cell Nucleus; Humans; Hyalin; Immunoenzyme Techniques; Keratins; Male; Middle Aged; Soft Tissue Neoplasms; Spinal Neoplasms; Vimentin

Keratin protein immunohistochemistry is a powerful diagnostic tool whose role has already been firmly established in many surgical pathology laboratories. Recent studies of the biology of keratin proteins have defined the heterogeneity of keratin protein expression among various epithelial tissues and their tumors and provide the basis for understanding the immunoreactivity of epithelial tumors with various keratin antibodies. Successful execution of the procedure requires attention to technical details such as the fixation of tissue, use of proteolytic enzymes such as trypsin for formalin-fixed tissues, and the choice of the appropriate antibody and controls. Broadly reactive polyclonal and monoclonal antibodies to keratins have been remarkably useful in identifying poorly differentiated and undifferentiated carcinomas. Monoclonal antibodies of restricted specificity and monospecific antibodies to keratin are under development and may prove helpful in defining the organ of origin of metastatic carcinomas. Keratin protein immunohistochemistry supplements existing information used by pathologists in diagnosis, and the immunohistochemical results should be interpreted in the light of the clinical findings, gross and microscopic pathology, and the results of any other special studies.

Topics: Animals; Antibodies; Antibodies, Monoclonal; Bone Neoplasms; Carcinoid Tumor; Carcinoma; Humans; Immunoassay; Keratins; Neoplasms; Sarcoma; Soft Tissue Neoplasms

Immunohistochemistry of intermediate filaments (IF) is a new and important way to evaluate the epithelial, mesenchymal, muscular, glial, or neural differentiation in tumors. This is based on the stable cell-type-specific expression of IF proteins in normal and neoplastic tissues. Immunohistochemical studies with antibodies to intermediate filaments have also given new perspectives in the histogenesis and biologic nature of many tumors. This article reviews both the recent findings and the authors' experience in the use of intermediate filament antibodies in tumor diagnosis and classification.

Topics: Adenocarcinoma; Antibodies, Neoplasm; Carcinoma, Squamous Cell; Desmin; Diagnosis, Differential; Glial Fibrillary Acidic Protein; Histocytochemistry; Humans; Immunochemistry; Keratins; Melanoma; Mesothelioma; Microfilament Proteins; Microscopy, Electron; Neoplasm Proteins; Neoplasms; Nervous System Neoplasms; Sarcoma; Soft Tissue Neoplasms; Thyroid Neoplasms; Urinary Bladder Neoplasms; Vimentin

RNA sequencing of unclassified soft tissue tumors has allowed for definition of multiple new entities. Antonescu et al. recently reported three case of low grade sarcoma with recurrent EWSR1/FUS::NACC1 fusion and distinctive storiform architecture that were suggestive of a novel tumor type.. Here, we present a case of an additional sarcoma with FUS::NACC1 fusion that arose in the head and neck and showed immunohistochemical evidence of epithelial differentiation.. A 41 year old woman presented with throat and inner ear pain and was found to have a nasopharyngeal mass. Biopsy highlighted a spindle cell neoplasm composed of bland cells arranged in a tight storiform pattern. On immunohistochemistry, the tumor cells were focally positive for S100 in a fibrillary pattern but were also positive for high molecular weight cytokeratin, p40, and CD34. RNA sequencing demonstrated a FUS::NACC1 fusion. The patient remains free of disease 2 years after surgical resection.. These findings confirm the previously-reported recurrent storiform histology in sarcomas with EWSR1/FUS::NACC1 fusion while simultaneously expanding the immunohistochemical spectrum of this entity to include overt epithelial differentiation. With involvement of a head and neck mucosal site, these findings also expand the differential diagnosis to include multiple mesenchymal entities including spindle cell squamous cell carcinoma. Further recognition of this emerging entity via expanded RNA sequencing panels will be necessary to determine the prevalence of these unique features.

Topics: Adult; Biomarkers, Tumor; Cell Differentiation; Female; Humans; Immunohistochemistry; Keratins; Neoplasm Proteins; Repressor Proteins; RNA-Binding Protein FUS; Sarcoma; Soft Tissue Neoplasms

Superficial CD34-positive fibroblastic tumor (SCPFT) is a fibroblastic/myofibroblastic soft tissue tumor of rarely metastasizing intermediate malignancy. Some recent studies have described a relationship between SCPFT and PRDM10-rearranged soft tissue tumor (PRT) based on SynCAM3 and PRDM10 expression on immunohistochemistry. We performed CD34, cytokeratin AE1/AE3, SynCAM3, and PRDM10 immunohistochemistry in SCPFT and its histological mimics, including myxoinflammatory fibroblastic sarcoma (MIFS), superficially localized myxofibrosarcoma (MFS), and undifferentiated pleomorphic sarcoma. We also examined cyclin D1 expression because it is expressed in MIFS and MFS. We conducted fluorescence in situ hybridization (FISH) of PRDM10 rearrangement in SCPFT cases. On immunohistochemistry, only SCPFT showed strong and diffuse SynCAM3 expression. SCPFT also exhibited strong nuclear and weak cytoplasmic cyclin D1 expression, which was similar to that observed in MIFS. Two of five SCPFT cases exhibited nuclear PRDM10 expression. FISH revealed PRDM10 split signals in 44% and 24% of tumor cells in two SCPFT cases showing nuclear PRDM10 expression on immunohistochemistry, respectively. A minority of non-SCPFT cases showed focal SynCAM3 expression, but a combination of SynCAM3 and cyclin D1 in addition to CD34 and cytokeratin AE1/AE3 may be useful for the differential diagnosis of SCPFT and its histological mimics.

Topics: Biomarkers, Tumor; Cyclin D1; Fibrosarcoma; Humans; Immunohistochemistry; In Situ Hybridization, Fluorescence; Keratins; Skin Neoplasms; Soft Tissue Neoplasms

Extraskeletal myxoid chondrosarcoma (EMC) is a rare form of adult sarcoma with distinct histology and NR4A3 gene fusion. Immunohistochemically, EMCs are variably positive for S100 protein and neuroendocrine markers. Unlike histologically similar soft-tissue myoepithelial tumours, keratin expression is rare. Prompted by two recent EMC cases with diffuse keratin expression, we investigated the expression of epithelial markers in a molecularly confirmed cohort of EMC and identified two additional similar cases.. Four keratin-positive EMCs occurred in one man and three women aged 46-59 years. All tumours displayed nonclassic histology with prominent stromal fibrosis, and keratin AE1/AE3 was expressed either diffusely (N = 2) or focally (N = 2). In one tumour, keratin expression was limited to the sclerotic area. All tumours coexpressed epithelial membrane antigen and two additionally expressed S100 protein or glial fibrillary acidic protein. All tumours harboured NR4A3 fusions, including TAF15::NR4A3 (N = 1) and EWSR1::NR4A3 (N = 3). Two cases were initially considered as most consistent with myoepithelial tumours based on widespread stromal fibrosis and keratin expression. DNA methylation analysis classified two tumours tested as EMCs.. We identified a small subset of EMCs characterised by keratin expression and prominent stromal fibrosis. This histological pattern must be recognised in the differential diagnosis of myoepithelial tumours because misclassification may lead to the erroneous prediction of tumour behaviour and may alter patient management. NR4A3 genetic analysis should be considered even in the face of keratin expression and prominent stromal fibrosis.

Topics: Adult; Calmodulin-Binding Proteins; Chondrosarcoma; Female; Fibrosis; Humans; Keratins; Male; Myoepithelioma; RNA-Binding Proteins; S100 Proteins; Soft Tissue Neoplasms

Giant cell tumor of soft tissue (GCT-ST) is a rare soft tissue neoplasm that is morphologically similar to but genetically distinct from giant cell tumor of bone. A novel keratin-positive GCT-ST (KPGCT-ST) harboring HMGA2::NCOR2 fusions was recently discovered. Fewer than 30 cases have been described; herein is reported an additional seven.. Cases diagnosed as GCT-ST were retrieved from institutional archives and consultation files. The histopathologic characteristics were assessed, and the electronic medical record was reviewed.. Seven tumors were identified in six women and one man with a median age of 23 years. All patients underwent excision; no recurrences or metastases were noted during a median follow-up period of 7 months. Histopathologically, the tumors were characterized by a multinodular proliferation of keratin-positive mononuclear cells with evenly admixed osteoclast-like giant cells and absent neoplastic bone. A fibrous capsule with lymphoid cuffing was frequently seen. Foamy macrophages, inflammation, hemorrhage, and hemosiderin were variably present. The HMGA2::NCOR2 fusion was detected in all cases.. Our findings support previously reported hypotheses that KPGCT-ST is a spectrum of the same entity as the recently described xanthogranulomatous epithelial tumor. Although follow-up data are limited, to date, KPGCT-ST appears to follow an indolent course.

Topics: Adult; Diagnosis, Differential; Female; Giant Cell Tumors; Giant Cells; Humans; Keratins; Male; Nuclear Receptor Co-Repressor 2; Soft Tissue Neoplasms; Young Adult

Myxoinflammatory fibroblastic sarcoma (MIFS) is a rare soft tissue tumor with a predilection for the distal extremities and a tendency for local recurrence. Morphologically, MIFS consists of spindle and bizarre epithelioid cells resembling virocytes embedded in a fibrous to myxoid stroma with an abundant inflammatory infiltrate. Importantly, the molecular landscape of MIFS is wide and includes: VGLL3 amplification, BRAF fusion/amplification and OGA/TGFBR3 rearrangements. In this study, we describe a variant of MIFS showing a frequent nodular configuration associated with necrosis and recurrent YAP1::MAML2 fusions. The cohort consisted of 7 patients (4 females and 3 males) ranging in age from 21 to 71 years (median: 47 years). Two tumors (28%) occurred in acral locations while the remaining cases were more widely distributed (thigh, n = 2; arm, n = 1; neck; n = 1; chest-wall, n = 1). Tumor size ranged from 10 to 38 mm (median: 20 mm). Histologically, lesions frequently presented as nodules with central areas of necrosis, and were predominantly composed of sheets of epithelioid cells with large vesicular nuclei and prominent nucleoli (Reed-Sternberg-like cells or virocytes). The stroma was mostly fibrous and showed a polymorphous inflammatory infiltrate. Myxoid stromal changes were focally seen in one case, and pseudolipoblasts were absent. The immunophenotype was nonspecific, with only pan-keratin (AE1-AE3) and cyclin D1 expression in a subset of cases. RNA-Sequencing detected YAP1::MAML2 fusions in 3/7 cases; aCGH showed no significant gene copy number variations in 4 tested cases, and FISH analysis showed no VGLL3 amplification in 1 tested case. Follow-up was available for 6 cases, ranging from 7 to 63 months (median: 42 months). Local recurrence and metastasis were not seen and one tumor showed spontaneous regression following initial biopsy. In conclusion, we describe a novel variant of MIFS with distinctive clinicopathological and molecular features for which we propose the term "nodular necrotizing" MIFS.

Topics: Cyclin D1; DNA Copy Number Variations; Female; Fibrosarcoma; Humans; Keratins; Male; Necrosis; Proto-Oncogene Proteins B-raf; RNA; Skin Neoplasms; Soft Tissue Neoplasms; Trans-Activators; Transcription Factors; YAP-Signaling Proteins

Xanthogranulomatous epithelial tumor (XGET) and keratin-positive giant cell-rich soft tissue tumor with HMGA2-NCOR2 fusion (KPGCT) are two recently described neoplasms with both distinct and overlapping clinical and histopathologic features. We hypothesized that XGET and KPGCT may be related and represent a histologic spectrum of a single entity. To test this, we sought to characterize the clinical, radiographic, immunohistochemical, ultrastructural and molecular features of additional tumors with features of XGET and/or KPGCT, which we refer to descriptively as keratin-positive xanthogranulomatous/giant cell-rich tumors (KPXG/GCT). The archives were searched for potential cases of KPXG/GCT. Clinical and imaging features were noted. Slides were assessed for histologic and immunohistochemical findings. Ultrastructural and next generation RNA sequencing-based analysis were also performed. Nine cases were identified arising in seven women and two men [median age of 33 years (range: 12-87)]. Median tumor size was 4 cm (range: 2.4-14.0 cm) and tumors presented in the thigh (2), buttock (1), forearm (2), groin (1), cranial fossa (1), ilium (1), and tibia (1). Morphologically, tumors were most frequently characterized by a fibrous capsule, with associated lymphoid reaction, enclosing a polymorphous proliferation of histiocytes, giant cells (Touton and osteoclast-types), mixed inflammatory infiltrate, hemorrhage and hemosiderin deposition, which imparted a variably xanthogranulomatous to giant cell tumor-like appearance. One case clearly showed mononuclear cells with eosinophilic cytoplasm characteristic of XGET. All cases expressed keratin and 7 of 9 were found to harbor HMGA2-NCOR2 fusions including cases with xanthogranulomatous appearance. One patient developed local recurrence and multifocal pulmonary lesions, which were radiographically suspicious for metastases. Shared clinical, histologic and immunohistochemical features, and the shared presence of HMGA2-NCOR2 fusions supports interpretation of KPXG/GCT as a single entity which includes XGET and KPGCT. Given limited clinical follow-up to date and rare cases with apparently aggressive findings, we provisionally regard these tumors as having uncertain biologic potential.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Child; Female; Giant Cell Tumors; Giant Cells; Hemosiderin; HMGA2 Protein; Humans; Keratins; Male; Middle Aged; Neoplasms, Glandular and Epithelial; Nuclear Receptor Co-Repressor 2; Oncogene Proteins, Fusion; Soft Tissue Neoplasms; Young Adult

DICER1-related tumors occur hereditary or sporadically, with high-grade malignancies sharing clinicopathological and (epi)genetic features. We compared 4 pleuropulmonary blastomas (PPBs) and 6 sarcomas by mutation analysis, whole transcriptome sequencing and methylation profiling. 9/10 patients were female. PPB patients were 0-4 years. 3/4 were alive; 2 without disease. One patient died of metastatic disease (median follow-up, 16 months). Sarcoma patients were 16-56 years. Locations included: uterine cervix/corpus (3/1), soft tissue back/shoulder (1) and paravertebral (1). 5/6 patients were alive; 2 developed metastases: intracranial (1) and lung and kidney (1) (median follow-up, 17 months). The deceased patient previously had a PPB and a Sertoli-Leydig cell tumor. Histologically, tumors showed atypical primitive-looking cells with incomplete rhabdomyoblastic differentiation and cartilage (n = 5). Immunohistochemistry demonstrated desmin- (n = 9/10), myogenin- (n = 6/10) and keratin positivity (n = 1/1). Eight cases harbored biallelic DICER1 mutations with confirmed germline mutations in 4 cases. Two cases showed a monoallelic mutation. By RNA expression- and methylation profiling, distinct clustering of our cases was seen demonstrating a close relationship on (epi)genetic level and similarities to embryonal rhabdomyosarcoma. In conclusion, this study shows overlapping morphological, immunohistochemical and (epi)genetic features of PPBs and DICER1-associated high-grade sarcomas, arguing that these neoplasms form a spectrum with a broad clinicopathological range.

Topics: DEAD-box RNA Helicases; Desmin; Female; Humans; Keratins; Male; Mutation; Myogenin; Pulmonary Blastoma; Rhabdomyosarcoma, Embryonal; Ribonuclease III; RNA; Soft Tissue Neoplasms

A 10-year-old peach-faced lovebird (Agapornis roseicollis) was evaluated for an ulcerated and painful mass at the location of a fracture 2 years previously. Whole body radiographs showed a humeral fracture with a presumptive neoplastic proliferation in the distal diaphysis. Right wing amputation was elected but the animal died during recovery from surgery. Histopathological examination of the amputated wing revealed an infiltrative sarcomatous neoplastic proliferation. Immunohistochemistry (IHC) was carried out to characterize the tumour using antibodies against vimentin, desmin, smooth muscle actin (SMA), S-100, ionized calcium-binding adapter molecule-1 (IBA-1), CD18, cytokeratin and epithelial membrane antigen (EMA). The mesenchymal component of the mass was immunolabelled for vimentin and SMA and sparse epithelial cells were immunopositive for cytokeratin. Very few scattered cells were immunopositive for CD18 and IBA-1. The final diagnosis was consistent with an undifferentiated sarcoma with intralesional hyperplastic epithelium. According to the location, the history of a previous fracture and the histological pattern and IHC profile, the tumour was classified as an undifferentiated sarcoma with entrapped air sac epithelium.

Topics: Agapornis; Animals; Bird Diseases; Keratins; Sarcoma; Soft Tissue Neoplasms; Vimentin

A 10-year-old female rabbit developed an unencapsulated and asymmetrical superficial dermal mass on the neck. The tumour was invasive with central ulceration and contained three different histological components, namely trichoblastomatous, basal cell carcinoma (BCC)-like and undifferentiated carcinomatous. In the trichoblastomatous component, which occupied most of the tumour, epithelial neoplastic cells formed ribbon-like cellular trabeculae with a palisaded appearance and stromal giant cells. The BCC-like component was a unique lesion composed of epithelial foci and sarcomatous stroma. The sarcomatous stroma consisted of pleomorphic mesenchymal cells with collagen fibres and frequent giant cells with one or more bizarre nuclei. In the undifferentiated carcinomatous component, neoplastic cells had a sheet-like growth pattern without trichoblastic or squamous differentiation. Immunohistochemically, neoplastic epithelial cells were positive for p63 and cytokeratin (CK) while the stromal and giant cells were immunopositive for vimentin but negative for CK and p63. This is the first report of a malignant trichoblastoma with a sarcomatous stroma in animals.

Topics: Animals; Carcinoma, Basal Cell; Epithelial Cells; Female; Keratins; Rabbits; Sarcoma; Skin Neoplasms; Soft Tissue Neoplasms

Here we describe a rare case of renal myeloid sarcoma, first discovered incidentally on routine urine analysis, which is one of the first of it's kind to be reported. We describe the vanishingly rare phenomenon of renal myeloid sarcoma presenting without haematological manifestation while also highlighting the often inevitable transformative nature of the disease. We also describe the unusual immunohistochemistry findings, in particular the cytokeratin expression, that is not usually typical of such cases. We briefly discuss use of PET-CT for the disease response monitoring. We summarize treatment that has included palbociclib, use of which was previously reported only in small series of patients with AML with KMT2A mutation.

Topics: Humans; Keratins; Kidney Neoplasms; Leukemia, Myeloid, Acute; Positron Emission Tomography Computed Tomography; Sarcoma, Myeloid; Soft Tissue Neoplasms

Giant cell tumors of soft tissue (GCT-ST) are rare low-grade neoplasms that were at one time thought to represent the soft tissue counterparts of GCT of bone (GCT-B) but are now known to lack the H3F3 mutations characteristic of osseous GCT. We present six distinctive giant cell-rich soft tissue neoplasms that expressed keratins and carried a recurrent HMGA2-NCOR2 gene fusion. Patients were five females and one male aged 14-60 years (median, 29). All presented with superficial (subcutaneous) masses that were removed by conservative marginal (3) or wide (2) local excision. The tumors originated in the upper extremity (2), lower extremity (2), head/neck (1), and trunk (1). Five patients with follow-up (median, 21 months; range, 14-168) remained disease-free. Grossly, all tumors were well-demarcated but not encapsulated with variable lobulation. Histologically, they were composed of bland plump epithelioid or ovoid to spindled mononuclear cells admixed with evenly distributed multinucleated osteoclast-type giant cells. Foci of stromal hemorrhage and hemosiderin were seen in all cases. The mitotic activity ranged from 2 to 14/10 high power fields (median: 10). Foci of necrosis and vascular invasion were seen in one case each. The mononuclear cells were immunoreactive with the AE1/AE3 keratin cocktail and less frequently/less diffusely for K7 and K19 but lacked expression of other lineage-associated markers. RNA-based next-generation sequencing revealed an HMGA2-NCOR2 fusion in all tumors. None of the keratin-negative conventional GCT-ST showed the HMGA2-NCOR2 fusion (0/7). Metaplastic bone (4/9) and SATB2 expression (3/4) were frequent in keratin-negative conventional GCT-ST but were lacking in keratin-positive HMGA2-NCOR2 fusion-positive tumors. The distinctive immunophenotype and genotype of these tumors strongly suggest that they represent a discrete entity, differing from conventional GCT-ST and other osteoclast-rich morphologic mimics. Their natural history appears favorable, although a study of additional cases and longer follow-up are warranted.

Topics: Adolescent; Adult; Aged; Child; Female; Giant Cell Tumors; HMGA2 Protein; Humans; Keratins; Male; Middle Aged; Nuclear Receptor Co-Repressor 2; Oncogene Fusion; Soft Tissue Neoplasms; Young Adult

Pseudomyogenic hemangioendothelioma (PMHE) is a new entity. It is an intermediate soft tissue tumor clinically and/or histopathologically mimicking some other high-grade malignant tumors and some inflammatory diseases. We report a case of PMHE on the left plantar surface of a 28-year-old woman. Histopathological examination of the resected specimen revealed spindle and epithelioid cells with plump and atypical nuclei proliferated in the dermis and subcutaneous fat tissue with marked fibroplasia. Both spindle and epithelioid cells had abundant eosinophilic cytoplasm. Neoplastic cells were diffusely positive for AE1/AE3, CK7, vimentin, CD31, FLI-1, ERG, and INI-1. From those findings, we made the diagnosis of PMHE. We describe the main points of differentiation between PMHE and diseases that have similar clinical and/or histopathological findings, including cellular dermatofibroma, spindle cell squamous cell carcinoma, epithelioid sarcoma, epithelioid hemangioendothelioma, epithelioid angiosarcoma, nodular or proliferative fasciitis, and granulomatous fibrosing granulation tissue due to a ruptured epidermal cyst.

Topics: Adult; Antiporters; Diagnosis, Differential; Female; Hemangioendothelioma, Epithelioid; Humans; Keratins; Platelet Endothelial Cell Adhesion Molecule-1; Proto-Oncogene Protein c-fli-1; SMARCB1 Protein; Soft Tissue Neoplasms; Transcriptional Regulator ERG; Vimentin

Diagnosis of an epithelioid sarcoma (ES) is challenging on fine needle aspiration cytology (FNAC) smears. There are few documented series describing cytopathologic features and immunostaining results of ESs. The present study describes cytopathologic features of seven cases of ES. All seven tumors occurred in males within age-range of 22-61 years; in sites, such as forearm (n = 3), hand (n = 2), thigh (n = 1), and inguinal region (n = 1). FNAC was performed for metastatic lesions (n = 5), recurrent lesions (n = 4), as well as for a primary diagnosis (n = 1). FNAC smears in most cases were moderate to hypercellular, composed of polygonal cells(seven cases) and spindle cells(three cases), arranged in loosely cohesive groups, non-overlapping clusters, and scattered singly, containing moderate to abundant cytoplasm, defined cell borders, vesicular nuclei, and discernible nucleoli. Variable cytopathologic features identified in certain cases were "rhabdoid-like" intracytoplasmic inclusions (n = 5), giant cells (n = 3), and interspersed scanty, metachromatic stroma (n = 4). Histopathologic examination revealed two cases of conventional-type ES, three of proximal/large cell-type ES, and two cases of mixed-type ES, displaying features of conventional and proximal subtypes. By immunohistochemistry (IHC), tumor cells were positive for cytokeratin (CK)(4/5), epithelial membrane antigen (EMA) (6/6), panCK (1/1), vimentin (3/3), and CD34 (7/7). Tumor cells were completely negative for INI1/SMARCB1 (0/2) and CD31 (0/5). In our settings, FNAC was mostly performed in recurrent and/or metastatic cases of ES, and rarely for a primary diagnosis of ES. Important cytopathologic features of ESs include loosely cohesive, non-overlapping clusters of polygonal cells with variable "rhabdoid-like" and spindle cells. Optimal diagnostic IHC markers in such cases include CK, EMA, AE1AE3, CD34, and INI1/SMARCB1. Clinical correlation is imperative in all cases. Diagn. Cytopathol. 2016;44:636-642. © 2016 Wiley Periodicals, Inc.

Topics: Adult; Antigens, CD34; Arm; Biomarkers, Tumor; Biopsy, Fine-Needle; Humans; Keratins; Male; Middle Aged; Mucin-1; Platelet Endothelial Cell Adhesion Molecule-1; Sarcoma; SMARCB1 Protein; Soft Tissue Neoplasms; Thigh; Vimentin

Small round blue-cell tumors (SRBCTs) of soft tissue, which mainly include rhabdomyosarcoma (RMS), synovial sarcoma (SS), and Ewing's sarcoma/peripheral primitive neuroectodermal tumors (EWS/ pPNETs), are malignancies with overlapping morphological and immunohistochemical characteristics. Immunohistochemistry is one of the most prevalent and convenient methods for pathological diagnosis; however, differentiation between SRBCT subtypes in the absence of valid diagnostic markers is still very challenging. The purpose of the present study was to investigate diagnostic immunohistochemistry for subtyping soft tissue SRBCTs.. Seventeen RMS, 25 SS, and 14 EWS/pPNETs were investigated. Reverse transcription RT-PCR and immunohistochemistry was performed to determine a diagnosis. Also, the expression of CD99, FLI1, PAX5, myogenin, and Keratin/EMA was assessed between subtypes. The sensitivity and specificity test was performed to evaluate their diagnostic significance.. The sensitivity and specificity of the target markers were evaluated as follows. FLI1 and CD99 expression displayed strong associations in EWS/pPNETs, with OR (95% CI) and p values of 3.82 (1.23 - 11.94), p = 0.021 and 123.50 (12.63 - infinity), p < 0.001, respectively. Keratin/EMA expression did not support the diagnosis of EWS/pPNETs [OR (95% CI) = 0.06 (0.01 - 0.53), p = 0.011]. Myogenin expression displayed strong association with RMS, with high sensitivity and specificity of 94.1% and 100%, respectively. Membrane expression of CD99 did not support the diagnosis of RMS [OR (95% CI) = 0.09 (0.01 - 0.75), p = 0.026]. Keratin/EMA expression strongly indicated SS [OR (95% CI) = 345.00 (29.44 - infinity), p = 0.00011. A ROC curve value of 0.94 indicated that keratin/EMA expression might be a promising biomarker for SS, while separate expression of FLI1 and CD99 did not support the diagnosis of SS. Similarly, myogenin expression in RMS might be a promising biomarker for RMS with a ROC curve value of 0.97.. Diagnosis of SRBCTs should be based on a comprehensive analysis involving morphology and immunoreactivity to a panel of markers.

Topics: 12E7 Antigen; Adolescent; Adult; Aged; Antigens, CD; Cell Adhesion Molecules; Child; Child, Preschool; Female; Humans; Immunohistochemistry; Keratins; Male; Middle Aged; Neuroectodermal Tumors; Odds Ratio; Proto-Oncogene Protein c-fli-1; Reverse Transcriptase Polymerase Chain Reaction; Rhabdomyosarcoma; Sarcoma, Ewing; Sarcoma, Synovial; Sensitivity and Specificity; Soft Tissue Neoplasms; Young Adult

Angiosarcoma (AS) is a rare soft tissue sarcoma showing endothelial differentiation as indicated by morphology and expression of CD31 (blood), D2-40 (lymphatic), factor VIII, and CD34 (both). We sought to examine the pattern of immunohistochemical markers of differentiation in AS and correlate these with outcome.. An AS tissue microarray (n = 70 specimens) was constructed for immunohistochemical analysis of CD31, CD34, factor VIII, D2-40, and pan-cytokeratin. Samples on this array were linked to clinicopathologic and outcome data for these patients. Univariate analyses were used to explore disease-specific survival (DSS) factors.. Nine metastatic, 23 localized, and 4 recurrent cases were included. Information about the tissue status (ie, primary or metastasis) was unavailable in 4 patients. Primary sites for the tumor included bone (n = 1), breast parenchyma (n = 11), breast skin (n = 4), heart (n = 5), skin (n = 8), soft tissue (n = 7), and unknown (n = 3). Three patients presented with multifocal disease (primary sites in these patients included breast, skin, and soft tissue). Metastatic sites included lung, bone, lymph nodes, brain, liver, and parotid. Of the 40 cases, 8 (20%) showed a pure or predominant epithelioid histology. Of the biomarkers evaluated by tissue microarray, 92% of tumors expressed at least one endothelial marker (factor VIII = 83%, CD31 = 80%, CD34 = 63%, and D2-40 = 43%) with 88% expressing 2 or more markers. Eighty-eight percent of tumors expressing D2-40 coexpressed CD31, an unusual combination in normal vessels. No endothelial marker clearly associated with disease-specific survival. Fifty percent (4/8) of epithelioid cases and 9% (3/32) of nonepithelioid cases showed keratin expression.. Unusual patterns and loss of endothelial markers are common in AS, suggesting use of multiple markers in challenging cases and perhaps indicating important biologic characteristics.

Topics: Antibodies, Monoclonal, Murine-Derived; Antigens, CD34; Biomarkers, Tumor; Biopsy; Disease-Free Survival; Endothelial Cells; Epithelial Cells; Factor VIII; Female; Hemangiosarcoma; Humans; Immunohistochemistry; Kaplan-Meier Estimate; Keratins; Lymphatic Metastasis; Male; Multivariate Analysis; Neoplasm Recurrence, Local; Platelet Endothelial Cell Adhesion Molecule-1; Predictive Value of Tests; Soft Tissue Neoplasms; Time Factors; Tissue Array Analysis; Treatment Outcome

Myoepithelial carcinoma of soft tissue (MEC) and cellular extraskeletal myxoid chondrosarcoma (cEMC) share striking similarities. In this paper, we compare ten MECs with five cEMCs. MEC patients had an equal gender distribution. The age range was 15-76 years (mean, 42 years). Tumours were located on extremities, pelvic girdle, vulva and neck. Follow-up, available for nine patients, ranged from 4 to 85 months (mean, 35 months). Five patients were alive without evidence of disease, two were alive with disease and two died 8 months after the initial diagnosis. cEMCs were from three males and two females with an age range of 37-82 years (mean, 57 years); they presented in extremities, shoulder and paravertebral/cervical. Follow-up, available for four patients, ranged from 6 to 220 months (mean, 61 months). All patients were alive, two with recurrences and/or metastases and two without evidence of disease. Morphologically, the distinction between these two entities was difficult since all cases exhibited features typically seen in myoepithelial tumours. Immunohistochemically, MECs expressed pan-keratin (80 %), epithelial membrane antigen (EMA; 57 %), S100 (50 %), alpha-smooth muscle actin (ASMA; 75 %), calponin (67 %) and p63 (25 %). S100 and EMA were expressed in 40 % of cEMC cases respectively with additional immunoreactivity for p63, ASMA and glial fibrillary acidic protein in one case. Pan-keratin was negative in all neoplasms. NR4A3 rearrangement was present in four of four cEMCs and in none of the MECs. In contrast, three of nine (33 %) MECs and four of five (80 %) cEMCs showed an EWSR1 rearrangement. In summary, MECs and cEMCs share clinical, morphological, immunohistochemical and genetic characteristics. The pathognomic rearrangement of NR4A3 is a useful diagnostic feature in identifying cEMCs.

Topics: Adult; Aged; Calmodulin-Binding Proteins; Chondrosarcoma; DNA-Binding Proteins; Female; Gene Rearrangement; Humans; Immunohistochemistry; In Situ Hybridization, Fluorescence; Keratins; Male; Middle Aged; Myoepithelioma; Receptors, Steroid; Receptors, Thyroid Hormone; RNA-Binding Protein EWS; RNA-Binding Proteins; Soft Tissue Neoplasms

Topics: Biomarkers, Tumor; Bone Neoplasms; Calcium-Binding Proteins; Calponins; Chondroblastoma; Diagnosis, Differential; Humans; Immunohistochemistry; Keratins; Magnetic Resonance Imaging; Male; Membrane Proteins; Microfilament Proteins; Middle Aged; Mixed Tumor, Malignant; S100 Proteins; Soft Tissue Neoplasms; Vascular Neoplasms

In this case report, we have described the fine needle aspiration cytology (FNAC) of epithelioid sarcoma (ES) in a 40-year-old female patient who presented with multiple nodular swellings over right forearm and single right axillary lymph node. The FNAC smear showed predominantly dispersed as well as three-dimensional clusters of malignant cells admixed with basement membrane like material. The individual cells were moderately pleomorphic with round to oval nuclei and moderate to abundant amount of cytoplasm. The neoplastic cells have well-defined cytoplasmic borders and intercellular spaces. The excision biopsy of the swelling of the forearm showed ES. The cytology features of ES are characteristic and a preoperative diagnosis is helpful for proper management of the case.

Topics: Adult; Axilla; Biomarkers, Tumor; Biopsy, Fine-Needle; Female; Humans; Keratins; Lymph Nodes; Lymphatic Metastasis; Sarcoma; Soft Tissue Neoplasms; Vimentin

Vulvar epithelioid sarcoma is a rare, undifferentiated soft-tissue sarcoma, with a high rate of local relapse, regional nodal spread and distant metastases. The aim of this study was to investigate the clinical features, diagnosis, treatment and prognosis of this malignancy.. We studied the clinicopathologic features of 20 cases of vulvar epithelioid sarcoma, of which 4 cases were admitted to our hospital from 1999 to 2009. All of the patients received radical local excision with inguinofemoral lymphadenectomy. Seven patients were treated without adjuvant therapy. Seven patients received postoperative radiotherapy only and three underwent chemotherapy. Chemotherapy plus radiotherapy were given postoperatively in three.. The patients ranged in age from 23 to 80 years (median: 36 y). The tumors ranged from 1 to 10 cm in their greatest diameter (median: 5.1 cm). All cases showed immunoreactivity for both vimentin and cytokeratin. Follow-up information on all 20 patients was available, and covered periods ranging from 3 to 104 months.11 patients were alive with no evidence of disease. 2 patients developed lymph node metastases but alive. 7 patients had died of the disease. Survival of the early stage (I-II) patients was significantly longer than those in the advanced stage (III-IV) (median, 21 vs. 6 months, P < 0.01). There was no significant difference between survival of patients with or without inguinofemoral lymphadenectomy (median, 11.5 vs. 6 months, P = 0.086).. Because of the relatively frequent misdiagnosis, a differential diagnosis combined with immunohistochemistry is needed to determine an early and accurate diagnosis. The tumor markers exhibiting immunoreactivity includ vimentin, epithelial membrane antigen (EMA) and cytokeratin (CK). Radical local excision with adequate margin (at least 2 cm) and bilateral inguinofemoral lymphadenectomy is effective for the treatment of vulvar epithelioid sarcoma. The role of adjuvant therapy, chemotherapy and radiation remains unclear but merits consideration.

Topics: Adult; Aged; Aged, 80 and over; Chemotherapy, Adjuvant; Female; Follow-Up Studies; Humans; Keratins; Lymph Node Excision; Lymphatic Metastasis; Middle Aged; Mucin-1; Neoplasm Staging; Radiotherapy, Adjuvant; Retrospective Studies; Sarcoma; Soft Tissue Neoplasms; Survival Rate; Vimentin; Vulva; Vulvar Neoplasms; Young Adult

Synovial sarcoma is a high-grade soft tissue sarcoma that can be challenging to diagnose on the basis of histology alone. It is defined by a characteristic translocation t(X;18) that produces the fusion oncogene SYT-SSX. The current diagnostic gold standard for synovial sarcoma is the demonstration of the translocation by fluorescence in situ hybridization, reverse transcriptase polymerase chain reaction, or cytogenetics, in an appropriate histologic context. TLE1 encodes a transcriptional corepressor that is overexpressed in synovial sarcomas. Gene and tissue microarray studies have identified TLE1 as an excellent bio-marker for distinguishing the synovial sarcoma from other soft tissue malignancies. We prospectively evaluated incoming soft tissue tumor cases where the histology and clinical setting made synovial sarcoma a real consideration in the differential diagnosis. TLE1, Bcl2, epithelial membrane antigen, and cytokeratin expression were assessed using commercially available antibodies. TLE1 gave intense, diffuse nuclear staining in 35 of 35 molecularly confirmed synovial sarcoma cases, and was rare to absent in the 73 other soft tissue tumors examined (positive staining was found only in 1 of 43 malignant peripheral nerve sheath tumors, the 1 tested fibrosarcoma, and 1 pleomorphic sarcoma). TLE1 was more sensitive and specific for synovial sarcoma than other currently available immunohistochemical markers including Bcl2, epithelial membrane antigen and cytokeratins, and had a positive predictive value of 92% and a negative predictive value of 100% in this clinical setting. Our findings confirm, in a prospective diagnostic context, that TLE1 is more sensitive and specific for synovial sarcoma than any other currently available immunohistochemical stains, and in some cases may preclude the need for molecular testing.

Topics: Biomarkers, Tumor; Co-Repressor Proteins; Gene Expression Regulation, Neoplastic; Humans; Immunohistochemistry; In Situ Hybridization, Fluorescence; Keratins; Mucin-1; Oncogene Proteins, Fusion; Predictive Value of Tests; Prospective Studies; Proto-Oncogene Proteins c-bcl-2; Repressor Proteins; Reverse Transcriptase Polymerase Chain Reaction; Sarcoma, Synovial; Sensitivity and Specificity; Soft Tissue Neoplasms

Synovial sarcomas are aggressive malignant soft tissue tumors typically observed in adolescents and young adults. They are often characterized by the chromosomal translocation t(X;18)(p11.2;q11.2), which results in the expression of SYT-SSX fusion transcripts. We describe the first case of synovial sarcoma observed in a human fetus. The tumor occurred in the left upper arm and led to intrauterine fetal demise during gestational week 31. Grossly, the tumor measured 10 x 8 x 8 cm, appeared pinkish in color, and developed in the soft tissues of the left arm surrounding the humerus. Histologically, this large tumor showed a dense proliferation of homogeneous spindle cells with some necrotic areas. The positive detection of the SYT-SSX1 fusion transcripts with reverse-transcription polymerase chain reaction in formalin-fixed and paraffin-embedded tissue confirmed the synovial sarcoma diagnosis.

Topics: Adult; Arm; Biomarkers, Tumor; Fatal Outcome; Female; Fetal Diseases; Humans; Immunohistochemistry; Keratins; Oncogene Proteins, Fusion; Reverse Transcriptase Polymerase Chain Reaction; Sarcoma, Synovial; Soft Tissue Neoplasms; Translocation, Genetic

Epithelioid sarcoma (ES) is a rare, aggressive soft tissue tumor with a characteristic predilection for adolescents and young adults, and a tendency to occur on distal extremities. We report a case of ES arising in an 80-year-old woman within a burn scar that histopathologically showed unusual 'angiomatoid' features. The patient presented initially with a solitary nodule on her right wrist arising at the site of a burn scar. Histopathologically, the tumor was composed of a proliferation of relatively bland, epithelioid and spindle cells focally arranged in a nodular pattern around areas of 'geographic' necrosis. In addition, there were prominent foci of hemorrhage and blood-filled spaces as well as tumor cells with intracytoplasmic vacuoles, features suggestive of an angiomatous process. Immunohistochemistry showed positivity of tumor cells for cytokeratins and epithelial membrane antigen (EMA) whereas all vascular markers tested were negative. The overall histopathologic features were consistent with a diagnosis of ES. Follow up showed multiple recurrences arising proximally along the right upper extremity. Our case underlines the clinical and histopathological heterogeneity of ES, emphasizing the unusual occurrence of ES with 'angiomatoid' features in the elderly. In this uncommon setting, this tumor should be especially distinguished from epithelioid hemangioendothelioma and epithelioid angiosarcoma. The significance of development of ES on a healed burn scar is uncertain, but may suggest a possible causal relationship.

Topics: Aged, 80 and over; Angiomatosis; Biomarkers, Tumor; Burns; Cicatrix; Female; Humans; Keratins; Mucin-1; Neoplasm Recurrence, Local; Sarcoma; Soft Tissue Neoplasms; Wrist

Clear cell sarcoma (CCS) of soft tissue is a rare sarcoma with morphologic similarities to malignant melanoma but a distinct genetic background including a chromosomal translocation, t(12;22)(q13;q12), or a resultant EWSR1-ATF1 fusion gene. In addition, the tumors occurring in the gastrointestinal tract may have a variant fusion gene EWSR1-CREB1. This study analyzed the clinicopathologic and molecular genetic features of 33 CCSs of soft tissue. The patients' ages ranged from 13 to 73 years (median, 30 y), and there was a male predominance (20 males, 13 females). The tumors were located in the deep soft tissues of the extremities (N=25) or in the trunk or limb girdles (N=8). The median tumor size was 4 cm (range, 1 to 15 cm). The tumor cells were either spindle or epithelioid, and they were arranged predominantly in a short fascicular (N=19) or a solid sheetlike growth pattern (N=14). Minor histologic variations included the existence of rhabdoid cells (N=8), bizarre pleomorphic cells (N=6), alveolar structures due to loss of cellular cohesion (N=3), and a seminomalike pattern (N=2). Tumor necrosis was evident in 14 tumors, and the mitotic activity ranged from 0 to 43 mitotic figures (MF)/10 high-power fields (HPF) (mean: 4 MF/10 HPF). Immunohistochemically, the tumors were consistently positive for S-100 protein (33/33) and variably or focally for HMB45 (32/33), microphthalmia transcription factor (26/32), Melan A (23/32), CD57 (25/33), bcl-2 (30/32), synaptophysin (14/32), CD56 (7/32), epithelial membrane antigen (12/33), cytokeratin (AE1/AE3) (1/32), CD34 (3/32), c-erbB-2 (10/32), c-kit (5/32), and c-met (5/32). alpha-Smooth muscle actin, desmin, and cytokeratin (CAM5.2) were negative. Reverse transcription-polymerase chain reaction using RNA extracted from formalin-fixed, paraffin-embedded tissues demonstrated transcripts of the EWSR1-ATF1 (31/33) or EWSR1-CREB1 fusion gene (2/33). In 26 cases with available clinical information, local recurrences and metastases developed in 2 and 15 patients, respectively. Ten patients were dead of the disease, and the overall survival rate was 63% at 5 years. However, no clinicopathologic or molecular variables associated with the patients' prognosis were identified. This study confirms that CCS is an aggressive soft tissue tumor with a melanocytic phenotype and wider morphologic variations than had been generally considered. In cases with unusual histologic findings, molecular detection of the EWSR1-ATF1/CREB1 fusio

Topics: Adolescent; Adult; Aged; Antigens, CD34; Antigens, Neoplasm; Calmodulin-Binding Proteins; CD57 Antigens; Cyclic AMP Response Element-Binding Protein; Female; Gene Fusion; Genes, bcl-2; Histocytochemistry; Humans; Immunohistochemistry; Keratins; Male; MART-1 Antigen; Melanoma-Specific Antigens; Microphthalmia-Associated Transcription Factor; Middle Aged; Mucin-1; Neoplasm Metastasis; Neoplasm Proteins; Neoplasm Recurrence, Local; Proteins; Proto-Oncogene Proteins c-kit; Proto-Oncogene Proteins c-met; Receptor, ErbB-2; RNA-Binding Protein EWS; RNA-Binding Proteins; S100 Proteins; Sarcoma, Clear Cell; Soft Tissue Neoplasms; Survival Rate; Synaptophysin; Translocation, Genetic

To assess the diagnostic values of immunohistochemistry and SYT-SSX fusion gene detection for synovial sarcoma.. Based on clinical features, histological and immunohistochemical profiles, 195 cases of tumors were divided into three diagnostic categories: definitive synovial sarcoma, probable synovial sarcoma and possible synovial sarcoma. RT-PCR Detection of the SYT-SSX fusion gene was performed using paraffin embedded tissue samples. Comparison between RT-PCR and immunohistochemistry results was carried out and their diagnostic value was evaluated.. There were 62 (31.8%) definite synovial sarcomas, 49 (25.1%) probable synovial sarcomas and 84 cases (43.1%) possible synovial sarcomas. SYT-SSX fusion gene was detected in 140 (78.2%) cases overall, including 94.7% (54/57) definite synovial sarcomas, 86.0% (37/43) probable synovial sarcomas and 62.0% (49/79) possible synovial sarcomas. In tumors in the certain and probable synovial sarcoma categories, the positive rates of epithelial membrane antigen (EMA) were significantly higher in the SYT-SSX positive cases than SYT-SSX-negative cases (P = 0.022, P = 0.010, respectively). EMA was positively correlated with the presence of SYT-SSX (r(s) = 0.431, P = 0.001, r(s) = 0.463, P = 0.002, respectively). However, such a correlation was not seen in cytokeratin (CK), vimentin or S-100 protein immunostains (P > 0.05). In tumors of possible synovial sarcoma category, there were no significant differences of CK, EMA, vimentin or S-100 protein between SYT-SSX-positive and SYT-SSX-negative tumors.. SYT-SSX fusion gene detection is not needed when the conventional approaches are diagnostic. EMA positivity has a similar diagnostic value to that of SYT-SSX by RT-PCR for tumors in the probable synovial sarcoma category. However, detection of SYT-SSX is very important for diagnosis of the tumors in the category of possible synovial sarcoma.

Topics: Adolescent; Adult; Aged; Biomarkers, Tumor; Child; Child, Preschool; Female; Humans; Immunohistochemistry; Keratins; Male; Middle Aged; Mucin-1; Oncogene Proteins, Fusion; Reverse Transcriptase Polymerase Chain Reaction; S100 Proteins; Sarcoma, Synovial; Soft Tissue Neoplasms; Vimentin; Young Adult

Topics: Adenocarcinoma, Clear Cell; Aged; Antimetabolites, Antineoplastic; Arm; Biomarkers; Biomarkers, Tumor; Deoxycytidine; Diagnostic Errors; Female; Gemcitabine; Humans; Keratins; Neoplasm Proteins; Neprilysin; Neuroendocrine Tumors; Pancreatic Neoplasms; Phosphopyruvate Hydratase; Soft Tissue Neoplasms; Subcutaneous Tissue; Vimentin

Ectopic hamartomatous thymoma (EHT) is a rare benign tumor. We present a case of EHT, which was seen as subcutaneous mass on the left supraclavicular area in a 19-year-old man. The tumor consisted of spindle cells, epithelial cells, adipose cells, and a small amount of lymphocytes, as described previously. Immunohistochemically, spindle cells were positive for keratin, a-smooth muscle actin, CD34 and vimentin, but negative for desmin and S-100 protein. Lymphocytes were positive for CD45RO but negative for CD20, CD1a, and CD99. Approximately, 5% of cells were positive for MIB-1 and no cells stained for p53 and bcl-2. Recognition of EHT is important and needs to be differentiated from high-grade sarcomas such as synovial sarcoma or glandular malignant peripheral nerve sheath tumor.

Topics: 12E7 Antigen; Adult; Antigens, CD; Antigens, CD1; Antigens, CD20; Antigens, CD34; Cell Adhesion Molecules; Choristoma; Diagnosis, Differential; Hamartoma; Humans; Keratins; Leukocyte Common Antigens; Male; Nerve Sheath Neoplasms; Sarcoma, Synovial; Soft Tissue Neoplasms; Thymoma; Thymus Neoplasms; Vimentin

MDM2 and CDK4 immunostaining can be useful adjuncts in diagnosing liposarcoma among soft tissue neoplasms. We examined the reproducibility of MDM2 and CDK4 staining between 2 laboratories and between tissue microarrays and whole tissue sections. Sixty-two soft tissue tumors were immunostained at the Bergonié Institute, Bordeaux, France, and the Curie Institute, Paris, France. We also examined 203 soft tissue neoplasms on standard tissue sections and tissue microarrays. There was high concordance of results obtained from the 2 laboratories (with 2 different pathologists) for MDM2 (kappa, 0.93) and CDK4 (kappa, 0.8) staining. There also was excellent concordance between results on tissue microarray and on whole tissue sections for MDM2 (kappa, 0.80) and CDK4 (kappa, 0.93). Immunostaining for MDM2 and CDK4 is a reproducible technique that may be exported to different laboratories for routine use. Tissue microarray is indicated for studying large series.

Topics: Biomarkers, Tumor; Humans; Immunoenzyme Techniques; Keratins; Observer Variation; Proto-Oncogene Proteins c-mdm2; Reproducibility of Results; Retrospective Studies; Sarcoma; Soft Tissue Neoplasms; Tissue Array Analysis

Myoepithelioma is a rare but well-characterized group of tumours, among which myoepithelioma of the salivary glands is the best known. We report two patients with myoepithelioma of parotid gland presenting as infra-auricular subcutaneous mass. The lesions were clinically suspected to be epidermal cyst. The biopsies revealed that most of the tumour cells showed epithelioid features with oval or spindle eosinophilic cytoplasm. No ductal or syringomatous epithelial structures were observed. The tumour cells showed cytoplasmic immunoexpressions of vimentin, cytokeratin (AE1/AE3), S-100 protein and smooth muscle actin (SMA). In one patient, a strong calponin positivity was observed. Maguetic resonance imaging (MRI) of both patients revealed exophytic, well-defined, strongly enhancing mass in superficial lobe of parotid gland, confirming the parotid gland origin. Myoepithelioma of parotid gland can be presented as a slowly growing tumour of pre- or infra-auricular area. In dermatologic department, it can be misdiagnosed as various dermal or subcutaneous tumours.

Topics: Actins; Adult; Biomarkers, Tumor; Diagnosis, Differential; Female; Humans; Keratins; Male; Middle Aged; Myoepithelioma; Parotid Neoplasms; S100 Proteins; Soft Tissue Neoplasms; Subcutaneous Tissue; Vimentin

Ewing's sarcoma/primitive neuroectodermal tumor (EWS/PNET) is an aggressive neoplasm of bone and soft tissue. Histologically, it is characterized by the presence of small round blue cells, which usually express MIC-2 and FLI-1 immunohistochemically. The most specific feature for diagnosis, however, is cytogenetic or molecular evidence of a consistent abnormality, the t(11;22)(q24;q12), or variants thereof. The immunohistochemical expression of keratins in a significant proportion of these cases has been highlighted in several recent studies. The ultrastructural features of these keratin-positive tumors have not, however, been characterized in detail. In this study we analyzed the ultrastructural features of 12 well-documented EWS/PNETs that stained strongly for pankeratin by immunohistochemistry. Ultrastructurally, the tumor cells contained a few organelles, which included a small number of mitochondria, poorly developed Golgi complexes, free ribosomes, and inconspicuous rough-endoplasmic reticulum. Rudimentary cell junctions were seen in 2 tumors while prominent junctions were observed in the remaining 10. Five tumors contained intracytoplasmic filaments, and definite tonofibrils were identified in 2. Well-developed basal lamina around tumor cells were also demonstrated in 2 tumors. Follow-up information was available for all cases. Seven patients died of disease, 2 are alive with disease, and 3 have no current evidence of disease. The cohort includes 5 patients with a type-1 translocation, which has been associated with a better prognosis in some studies; 4 of these patients have died of their disease, and 1 is alive with recurrent disease. This study shows that keratin-positive EWS/PNETs have evidence of epithelial differentiation ultrastructurally, and may possibly represent a more aggressive subset of the EWS/PNET group of tumors.

Topics: Adolescent; Adult; Biomarkers, Tumor; Bone Neoplasms; Child; Fatal Outcome; Female; Humans; Immunohistochemistry; Keratins; Male; Microscopy, Electron, Transmission; Neuroectodermal Tumors, Primitive, Peripheral; Oncogene Proteins, Fusion; Proto-Oncogene Protein c-fli-1; Reverse Transcriptase Polymerase Chain Reaction; RNA-Binding Protein EWS; RNA, Neoplasm; Sarcoma, Ewing; Soft Tissue Neoplasms; Transcription Factors

To see the distribution of Calretinin, thrombomodulin, CK5/6 and HBME-1 markers in various subtypes of mesotheliomas and extend the published data on this topic. The positivity of adenocarcinoma specific markers (CEA and BerEP4) in malignant mesotheliomas have also been evaluated.. Various markers in 173 cases of malignant mesotheliomas received over a period of 8 years were evaluated by immunohistochemistry.. In majority of malignant mesotheliomas i.e., epithelioid and biphasic types, the positive staining patterns complement the gold standard histologic diagnosis. However, in a small minority mainly sarcomatoid variant, heavy reliance cannot be placed on these markers. CEA and BerEP4 are useful negative markers of mesotheliomas, although occasionally these are positive in clear cut mesotheliomas.. Specificity of various markers in malignant mesotheliomas should be assessed according to histologic subtypes. The existing generation of markers is not reliable in diagnosis of sarcomatoid mesotheliomas. Fortunately this forms only a small group of mesothelial malignancy. In common epithelioid and biphasic variants calretinin, thrombomodulin, CK5/6, HBME-1 are sensitive positive markers whereas CEA and BerEP4 are negative markers of malignant mesotheliomas.

Topics: Antigens, Neoplasm; Antigens, Surface; Biomarkers, Tumor; Calbindin 2; Coloring Agents; DNA-Binding Proteins; Humans; Immunohistochemistry; Keratins; Lewis X Antigen; Mesothelioma; S100 Calcium Binding Protein G; Sarcoma, Synovial; Soft Tissue Neoplasms; Thrombomodulin

Malignant myoepithelioma of soft tissue is extremely rare. Presented herein is a case arising in a 17-year-old man. The tumor was initially noticed as a painless deep soft-tissue mass in the right forearm when the patient was aged 3 years. Thereafter, it grew without remarkable symptoms, such as pain or tenderness, until his visit to the hospital because of swelling of his forearm when he was 17 years old. An excisional biopsy specimen disclosed an invasive tumor exhibiting a lobular architecture. The tumor cells were arranged in a reticular and/or trabecular fashion with a myxoid background, and nuclear atypia was evident. Mitoses and tumor necrosis were also observed. Immunohistochemically, S-100 protein and epithelial markers were diffusely positive. Faint intercellular junctions and basal laminae were identified by electronmicroscopy. On the basis of these findings, the tumor was diagnosed as a malignant myoepithelioma of soft tissue. Six months later, multiple lung metastases were observed, and an open biopsy revealed a neoplasm displaying the same histological feature as the previously biopsied specimens. The patient died of his disease 18 months after the lung biopsy. Malignant myoepithelioma should be kept in mind in diagnosis of deep soft-tissue tumors with epithelioid features.

Topics: Adolescent; Fatal Outcome; Humans; Immunohistochemistry; Keratins; Male; Microscopy, Electron; Mucin-1; Myoepithelioma; S100 Proteins; Soft Tissue Neoplasms

Extraskeletal chordoma arising within soft tissue is a rare occurrence. We report a case of chordoma that is unusual both for its location within the subcutaneous soft tissue of the sacrococcygeal region without involvement of adjacent bones and for the presence of eosinophilic roundish inclusion bodies within the cytoplasm of tumor cells. These bodies revealed immunoreactivity for cytokeratin and a fibrillar, partly whorled structure on the electron microscopic examination, consistent with an intermediate filament-based composition. To our knowledge, this is the first report of chordoma featuring this cellular change although we do not know the significance of these bodies.

Topics: Biomarkers, Tumor; Chordoma; Humans; Immunohistochemistry; Inclusion Bodies; Intermediate Filaments; Keratins; Male; Middle Aged; Sacrococcygeal Region; Soft Tissue Neoplasms; Treatment Outcome

We discuss here five cases of epithelioid sarcoma (ES) with final diagnosis established after reexamination of initial findings. Problems with differential diagnosis of these neoplasms arise since their microscopic picture may simulate several other pathological conditions such as non-neoplastic granulomatous reactions, squamous cell carcinomas and adenocarcinomas, melanomas and soft tissue sarcomas with epithelioid component. Final ES diagnosis requires presence of cytokeratin, EMA and vimentin in neoplastic cells, as confirmed by immunohistochemical reactions. Differential diagnosis is also helped by concurrent cytology assessment that allows recognizing more easily such characteristic features as presence of plasmacytoid or spindle-shaped cells.

Topics: Adenocarcinoma; Adult; Aged; Antigens, CD34; Carcinoma, Squamous Cell; Diagnosis, Differential; Female; Granuloma; Humans; Immunohistochemistry; Keratins; Male; Melanoma; Middle Aged; Mucin-1; S100 Proteins; Sarcoma; Soft Tissue Neoplasms; Vimentin

There has been no report on useful immunohistological markers for epithelioid sarcoma (ES) so far. The purpose of this study is to evaluate the positivity and specificity of CA125 as a marker for the correct diagnosis of ES.. This study was performed in 11 patients with ES (nine men and two women; distal type: 10 cases; proximal type: one case), 78 patients with other soft tissue tumors and nine with benign granulomas. The other soft tissue tumors consisted of six synovial sarcomas, six clear cell sarcomas, eight leiomyosarcomas, six rhabdomyosarcomas, five malignant peripheral nerve sheath tumors, ten malignant fibrous histiocytomas, 17 desmoid tumors, 14 liposarcomas, six squamous cell carcinomas (cutaneous SCC of the distal extremities), two rheumatoid nodules and seven foreign body granulomas. Immunohistochemical analysis for CA125 was performed for these 89 soft tissue tumors and nine granulomas using a labeled streptavidin biotin method. Immunohistochemical analysis of epithelial membrane antigen, cytokeratin, carcinoembrionic antigen, vimentin and CD34 was performed only for the 11 ES patients.. CA125 was strongly expressed in 10 out of the 11 ES patients. EMA, cytokeratin and vimentin were also positive in all the cases. CEA was positive in two of the 11 patients. Immunohistochemical study in six ES patients showed expression of CD 34. The other 78 soft tissue tumors and nine granulomas did not express CA125.. This study clearly revealed the specificity and positivity of CA125 in ES. These data indicate that CA125 may be a useful tumor marker for diagnosing ES.

Topics: Adolescent; Adult; Antibodies, Monoclonal; Antigens, CD34; Biomarkers, Tumor; CA-125 Antigen; Carcinoembryonic Antigen; Carcinoma, Squamous Cell; Female; Granuloma; Humans; Immunohistochemistry; Keratins; Male; Middle Aged; Mucin-1; Rhabdomyosarcoma; Sarcoma; Sarcoma, Clear Cell; Sarcoma, Synovial; Sensitivity and Specificity; Soft Tissue Neoplasms

The clinical, radiological and pathologic features of a biphasic synovial sarcoma in the left elbow joint of a two-year-old male Rottweiler are presented. The tumor showed positive immunoreactivity for vimentin, Epithelial Membrane Antigen (EMA), p53 and PCNA, while it was negative for the cytokeratin used, S-100, Rb and p21. Immunohistochemistry for EMA allowed the identification of epithelioid components of synovial sarcoma, and may, therefore, contribute in establishing a diagnosis of biphasic synovial sarcoma. Intratumoral variation in PCNA immunoreactivity was minimal, indicating that the various tumor components proliferate at more or less similar rates. Overall, the characterized immunohistochemical profile for canine synovial sarcoma, not defined previously, may provide clues to the histogenesis of the phenotypically mesenchymal and epithelial elements of the tumor, and may be of value in the differential diagnosis of challenging cases, decreasing the risk of under- and mis-diagnosis. Although more cases need to be studied to determine whether there is a consistent pattern of immunostaining in canine synovial sarcoma, its potential significance is discussed in relation to the histogenesis, molecular pathology and differential diagnosis of canine synovial sarcoma.

Topics: Animals; Dog Diseases; Dogs; Elbow Joint; Forelimb; Histocytochemistry; Immunohistochemistry; Keratins; Male; Mucin-1; Oncogene Protein p21(ras); Proliferating Cell Nuclear Antigen; Radiography; Retinoblastoma Protein; Sarcoma, Synovial; Soft Tissue Neoplasms; Tumor Suppressor Protein p53; Vimentin

Epithelioid sarcoma (ES) is a rare malignant soft tissue tumor of uncertain histogenesis that arises predominantly in the extremities of young adults. Immunohistochemically, the neoplastic cells are typically positive for vimentin, low molecular weight cytokeratin (CAM5.2) and epithelial membrane antigen (EMA).. We examined eight cases of ES from seven different patients. All cases were studied with immunohistochemistry for EMA, CAM5.2 (keratin 8 and 18), 34BE12 (keratins 1, 5, 10 and 14/15), cytokeratins 7 and 20 (CK7, CK20), and CD34.. The average patient age was 53 (range 43-76) and the male:female ratio was 5:2. The location was the upper extremity in five tumors, the lower extremity, the perineum, and the paraspinal soft tissue in one tumor each. All cases contained predominantly epithelioid cells, but spindle cells were also present in three cases. All cases contained areas of geographic necrosis. CAM5.2 was strongly positive in seven tumors and focally positive in one (8/8). EMA was diffusely positive in two cases and focally positive in five cases (7/8). CD34 was diffusely positive in 3/8 cases. 34BE12 was diffusely positive in one case and focally positive in two others (3/8). CK7 was diffusely positive in one case and focally positive in another (2/8). CK20 was negative in all cases (0/8). All cases tested were positive for vimentin (6/6), 2 cases were focally positive for HHF35 (2/5), and all cases tested were negative for S-100 protein (0/7).. In addition to the known immunoreactivity for CAM5.2 and EMA, there is positivity for CK7 and 34BE12 in a small proportion of cases. None of the cases expressed CK20. This immunophenotypic profile suggests that ES is more similar to carcinoma and synovial sarcoma than to other soft tissue tumors, and may be of diagnostic utility.

Topics: Adult; Aged; Biomarkers, Tumor; Combined Modality Therapy; Disease-Free Survival; Female; Humans; Intermediate Filament Proteins; Keratin-20; Keratin-7; Keratins; Male; Middle Aged; Necrosis; Sarcoma; Soft Tissue Neoplasms

Myoepithelioma of soft tissues is a rare and under-recognized tumor. We report a case of a myoepithelioma arising in the soft tissue of the wrist in a 37-year-old man. This 3cm, nodular, well circumscribed tumor consisted of a mixture of spindle and epithelioid cells in a fibrous or focally myxoid stroma. Nuclear atypia were mild and mitotic activity was 1 mitotic figure per 10 high-power fields. No tubular epithelial structure was found. The tumoral cells expressed cytokeratin (KL1) and S-100 protein. Smooth muscle actin and desmin were negative. The excision was complete. At 5 months, no recurrence was noted. Myoepithelioma of deep soft tissue has a predilection for extremity involvement. It has to be differentiated from extraskeletal myxoid chondrosarcoma, parachordoma and synovial sarcoma. Most of myoepitheliomas are benign. However, metastasis may occur in a minority of cases.

Topics: Actins; Adult; Cell Nucleus; Desmin; Epithelial Cells; Humans; Keratins; Male; Mitosis; Myoepithelioma; S100 Proteins; Soft Tissue Neoplasms

Myxoid neurothekeomas (nerve sheath myxomas) are rare benign cutaneous neoplasms that may morphologically mimic other myxoid neoplasms of skin and soft tissue. The cytologic and histopathologic features of this lesion may resemble various myxoid sarcomas, chordoma, myxoid neurofibroma, dermal cutaneous mucinosis, and cutaneous myxoma as well as other myxoid or chondroid neoplasms. In this study, a myxoid neurothekeoma was analyzed using multiple techniques. We found that myxoid neurothekeomas reveal a nonspecific pattern by fine-needle aspiration, including stellate cells embedded within an abundant metachromatic myxoid stromal matrix. These are cytologic features shared by various other subcutaneous neoplasms and thus may not be helpful in forming a definitive diagnosis. Histopathologically, the tumor is composed of nodules of myxoid stroma containing interspersed bland spindled and stellate cells. Immunohistochemical studies show tumor cell positivity for S-100 protein and vimentin, a profile shared by other neoplasms with similar cytologic features and therefore of little diagnostic value. The histologic and cytologic differential of subcutaneous and soft tissue myxomatous lesions is broad and, therefore, is of unique value to the cytopathologist to consider myxoid neurothekeomas among the differential of other myxomatous neoplasms.

Topics: Biopsy, Needle; Desmin; Diagnosis, Differential; Humans; Immunohistochemistry; Keratins; Male; Neurothekeoma; Nose Neoplasms; S100 Proteins; Soft Tissue Neoplasms; Vimentin

Extrarenal malignant rhabdoid tumor (MRT), which is recognized as being histologically similar to renal MRT, is characterized by the presence of "rhabdoid cell" (RC) and a highly aggressive biological behavior. Recently it has been proposed that "proximal variant" of epithelioid sarcoma (ES), whose morphology is similar to that of MRT, actually has a more aggressive clinical course than classical type ES. Detailed immunohistochemical analysis of cytokeratin (CK) subunits was performed in 3 cases of extrarenal MRT, 3 cases of renal MRT, and 11 cases of ES comprising 2 "proximal variants" and 9 classical types. Renal and extrarenal MRTs showed positive immunoreactivity for both CK8 and CK18. Classical type ESs were diffusely positive, not only for CK8 and CK18, but also for other cytokeratin subunits including CK4, 6, 10, 13, 16, 17, and "high-molecular-weight" CKs (CK1, 5, 10, and 14). On the other hand, proximal ES revealed limited immunohistochemical reactivity for cytokeratins, compared with classical ES. In conclusion, the inclusion bodies of RCs show immunoreactivity confined to CK8, CK18, and vimentin. Furthermore, ES has additional CK expressions, while proximal ES possesses characteristics intermediate between those of classical ES and those of external MRT.

Topics: Adult; Aged; Child; Child, Preschool; Female; Humans; Immunoenzyme Techniques; Inclusion Bodies; Infant; Intermediate Filaments; Keratins; Kidney Neoplasms; Male; Middle Aged; Rhabdoid Tumor; Sarcoma; Soft Tissue Neoplasms; Survival Analysis

Sclerosing epithelioid fibrosarcoma (SEF) was first described in 1995 and since then 39 cases have been reported. Here we describe 6 cases of SEF (3 in women and 3 in men). The patients aged from 22 to 79 years. The tumours were located in soft tissues of the extremities (in 3 cases in the lower, in 2 instances in the upper extremity) and of the trunk (in 1 case). The lesions were partially nodular, of gray-white colour, and hard in consistency. Histologically, they were composed of epithelioid round to ovoid small cells with a sparse cytoplasm and a very low mitotic activity. The tumour cells formed cords and alveoli or were scattered individually within a dense hyalinized collagenous stroma. The neoplasms also contained foci of conventional fibrosarcoma, necrosis, calcification, and metaplastic bone. On immunohistochemistry, the neoplastic cells were positive for vimentin. Two cases were immunoreactive for epithelial membrane antigen and one tumour also for cytokeratins. The proliferative activity, assessed by MIB 1 antibody (Ki-67), was detected in 1-6% of neoplastic cells in primary tumours. Follow-up information was available in 5 patients. In two cases, there were local recurrences and distant metastases (in the lungs, upper extremity, and mediastinum). One of these patients died of SEF. The differential diagnosis of this relatively low-grade fibrosarcoma is broad and includes, along with a variety of benign and malignant soft tissue lesions, infiltrating carcinoma, and, to a lesser extent, sclerosing lymphoma.

Topics: Adult; Aged; Female; Fibrosarcoma; Humans; Immunohistochemistry; Keratins; Ki-67 Antigen; Male; Middle Aged; Mucin-1; Sclerosis; Soft Tissue Neoplasms; Vimentin

Topics: Adult; Fingers; Humans; Immunohistochemistry; Keratins; Male; Mucin-1; Necrosis; Sarcoma; Soft Tissue Neoplasms

Cytokeratin-positive interstitial reticulum cells (CIRCs) have been described as a subset of fibroblastic reticulum cells (FBRCs) normally found in lymph nodes, the spleen, and tonsils. Although tumors derived form other reticulum (dendritic) cells, specifically follicular dendritic cells, interdigitating dendritic cells, and cytokeratin-negative FBRCs, have been well documented and are now accepted, this is not the case for tumors of CIRCs. A possible reason for this failure is the difficulty in distinguishing them from other tumors, particularly carcinoma. We report three cases of cytokeratin-positive malignant tumors with a reticulum cell morphology: two located in the mediastinum and one in the soft tissue in the proximal forearm. All cases coexpressed vimentin, and one case coexpressed smooth muscle actin and desmin, resulting in a phenotype similar to that of some normal CIRCs. Although metastatic carcinoma from an occult or regressed primary tumor cannot be excluded completely, we raise the possibility of a CIRC origin for these cases.

Topics: Actins; Adult; Aged; Biopsy; Cytoplasm; Dendritic Cells; Desmosomes; Diagnosis, Differential; Female; Humans; Immunohistochemistry; Keratins; Lymph Nodes; Lymphatic Metastasis; Male; Mediastinal Neoplasms; Mediastinum; Middle Aged; Phenotype; Soft Tissue Neoplasms; Vimentin

Although 'aberrant' expression of the epithelial markers, cytokeratin (CK) and epithelial membrane antigen (EMA), in leiomyosarcoma has been described previously, there has not been a study of this phenomenon with clinicopathological correlation in a large series of lesions at different anatomical sites. We investigated systematically the immunohistochemical reactivity for CK and EMA in 100 cases of leiomyosarcoma. CK and EMA were positive in 38% and 44% of the cases, respectively. Although staining was usually focal, extensive immunoreactivity was observed in 11% with CK and 6% with EMA. There was no correlation between immunoreactivity for CK and EMA in leiomyosarcomas and non-neoplastic smooth muscle at the same location. Immunoreactivity for CK and EMA was not correlated with the location, age, sex, histological grade, or histological features, except for more frequent EMA positivity in vascular and uterine tumors than in soft tissue cases. These results indicate that CK and/or EMA-positive leiomyosarcomas do not have distinctive clinicopathological features differing from those of negative cases. However, the considerable frequency of immunoreactivity for these epithelial markers in leiomyosarcoma, occasionally with diffuse and strong immunopositivity, should be recognized as a potentially serious diagnostic pitfall in the differential diagnosis of other malignant spindle cell neoplasms.

Topics: Abdominal Neoplasms; Adult; Aged; Aged, 80 and over; Biomarkers; Female; Humans; Immunoenzyme Techniques; Keratins; Leiomyosarcoma; Male; Middle Aged; Mucin-1; Muscle, Smooth; Skin Neoplasms; Soft Tissue Neoplasms; Uterine Neoplasms; Vascular Neoplasms

We report a case of recurrent parachordoma of the left anterior tibial region in a 64-year-old male patient. The tumor was a periosteal tender mass, and, histologically, displayed vague nodules of spindle to rounded eosinophilic cells embedded in a myxoid matrix. Large vacuolated (physalphorouslike) cells were noted as in sacrococcygeal chordoma. This tumor should be differentiated from myxoid chondrosarcoma, myxoid liposarcoma, chondromyxoid fibroma, and metastatic chordoma. The presence of physaliphorous cells in the tumor with positive immunoreactions caused by cytokeratin rules out the diagnosis of another myxoid tumor. The differential diagnosis from metastatic chordoma is basically made by clinicians. Even though parachordoma is usually regarded as a benign soft tissue neoplasm, two recurrences occurred in our case. Since the reported cases, including ours, have diverse clinical courses, it is essential to follow-up the patient carefully.

Topics: Chondrosarcoma; Chordoma; Diagnosis, Differential; Humans; Immunohistochemistry; Keratins; Male; Middle Aged; S100 Proteins; Soft Tissue Neoplasms; Tibia; Vimentin

Hepatocellular carcinoma is relatively rare in the United States, and the patterns of extrahepatic manifestations are diverse. Disease dissemination occurs through hematogenous routes to frequently involve the lungs, bone, adrenal glands, and pancreas. Soft tissue metastasis is extremely rare and mandates systematic pathologic analysis, which may include the use of immunohistochemical staining for tumor-specific markers. Relevant tumor markers that can assist in localizing the site of origin for adenocarcinoma include carcinoembryonic antigen, alpha-fetoprotein, vimentin, and anticytokeratins. We detail the utility of immunohistochemistry in evaluating tumors of unknown origin.

Topics: Aged; alpha-Fetoproteins; Biomarkers, Tumor; Biopsy; Carcinoembryonic Antigen; Carcinoma, Hepatocellular; Humans; Immunohistochemistry; Keratins; Liver Neoplasms; Male; Soft Tissue Neoplasms; Vimentin

We present a rare case of primary extracranial meningioma in a 36-year-old man, who had a solitary multinodular mass located in the plantar muscle of the foot. The histology of specimens from simple excision was typical of meningioma, showing bland spindle cell proliferation with a whorl pattern. Immunohistochemical analysis demonstrated that the tumor cells showed diffuse and strong positivity for epithelial membrane antigen as well as moderate reactivity for cytokeratin and vimentin. Ultrastructurally, the tumor cells were characterized by thin bipolar cytoplasmic processes and joined by multiple small desmosomes. There were frequent pinocytotic vesicles and a distinct external lamina on the cell surface. These findings suggest that this primary ectopic meningioma, arising in the soft tissue, may have been derived from perineurial cells of the peripheral nerve, but was morphologically distinguishable from perineurioma. Primary extracranial meningioma should be included in the differential diagnosis of soft-tissue spindle cell tumors, especially those of peripheral nerve origin.

Topics: Adult; Diagnosis, Differential; Foot Diseases; Humans; Immunohistochemistry; Keratins; Male; Meningioma; Nerve Sheath Neoplasms; Soft Tissue Neoplasms; Vimentin

Vascular endothelial cells are specialized mesenchyme-derived epithelial-like lining cells which are the essential participants in benign and malignant vascular tumors. Although endothelia in lower animals often express keratins (K), human endothelia are generally K negative and vimentin-positive. However, K expression has been noted in some endothelia and in some epithelioid vascular tumors. In this study, we systematically examined normal human vascular endothelia and a spectrum of human vascular tumors (n = minimum of 137 tumors with each marker) for simple epithelial keratin polypeptides of the Moll catalogue (K7, K8, K18, and K19). Selected vascular tumors were also evaluated with antibodies to K14 and the monoclonal antibody 34betaE12 that recognizes several keratins of stratified epithelia. Endothelia of normal veins, venules, and lymphatics commonly exhibited focal positivity for K7 and K18, whereas K8, K14, and K19 were not seen in non-neoplastic endothelia with the antibodies used. Lymphangiomas (6 of 7) and venous hemangiomas (6 of 13) often showed K7-positive endothelial cells; K18 was detected less commonly, whereas K8 and K19 were not detected. Epithelioid hemangioendotheliomas (EHEs) showed K7 and K18 expression in the majority of cases (50% and 100%, respectively), while K8 was seen in 10% cases and K14 and K19 in none. In contrast, epithelioid angiosarcomas (EAs) were often positive for K8 and K18 (approximately 50%), whereas they less commonly showed K7 and only occasionally K19; all tumors were negative for K14 and with the antibody 34betaE12. Nonepithelioid angiosarcomas (AS) less commonly showed keratin expression with K7, K8, and K18 being positive in 20% of cases, and K14 and K19 in none of the cases. Epithelial membrane antigen (EMA) was occasionally detectable in EHE (2/19) but was present in 4 of 16 (25%) EAs and 17 of 48 (35%) nonepithelioid AS. These findings document the common presence of focal reactivity for K7 and K18 in subsets of normal endothelia and also the frequent presence of simple epithelial keratins in malignant vascular tumors, while such expression is uncommon in nonepithelioid angiosarcomas. K- and EMA-positivity in neoplastic endothelia needs to be considered in the evaluation of human tumors. K antibodies such as those specific to K19 or AE1 that do not react with K8 and K18 should be used in the differential diagnosis of epithelioid vascular tumors and carcinomas.

Topics: Biomarkers, Tumor; Diagnosis, Differential; Endothelium, Vascular; Hemangioendothelioma, Epithelioid; Hemangiosarcoma; Humans; Immunoenzyme Techniques; Keratins; Lymphangioma; Soft Tissue Neoplasms

We describe 12 cutaneous and soft tissue myoepitheliomas, most of them in elderly patients. Morphologically the cutaneous and soft tissue myoepitheliomas revealed the same spectrum as their salivary gland counterparts. They were composed of a mixture of spindle, epithelioid and clear myoepithelial cells. Immunohistochemically they were positive to keratins and S-100 protein and reacted inconsistently with antibodies to smooth muscle actin. Morphologically they lacked any folliculo-sebaceous or apocrine differentiation. We believe that they are related to the eccrine type of cutaneous mixed tumours. Most cases had a benign behaviour, but 1 tumour metastasized, and the patient died of the tumour. Myoepitheliomas of soft tissues should be distinguished from other neoplasms with epithelial differentiation and from ossifying fibromyxoid tumour of soft parts, parachordoma and extraskeletal myxoid chondrosarcoma.

Topics: Adult; Aged; Aged, 80 and over; Female; Humans; Immunohistochemistry; Keratins; Male; Middle Aged; Myoepithelioma; S100 Proteins; Skin Neoplasms; Soft Tissue Neoplasms

Monophasic synovial sarcoma (MSS) and malignant peripheral nerve sheath tumor (MPNST) are spindle cell sarcomas with overlapping histologic features, and their immunophenotypes may overlap, since MPNSTs express S-100 protein in only 50% to 60% of cases and rarely express epithelial markers, whereas MSSs can express S-100 protein in up to 40% of cases. We immunostained 29 cases of MSS and 29 cases of MPNST with antibodies to AE1/AE3, CAM 5.2, epithelial membrane antigen (EMA), S-100 protein, and cytokeratin subsets 7 and 19. Inclusion criteria for MSS included a consistent histology with expression of at least 1 epithelial marker. Inclusion criteria for MPNST included a tumor with a consistent histology arising in a patient with neurofibromatosis type 1 and/or in a plexiform neurofibroma, or ultrastructural confirmation of clear-cut schwannian differentiation. By definition, all cases of MSS were positive for at least 1 epithelial marker. Ten cases showed focal S-100 protein immunoreactivity, and 26 cases stained for cytokeratins 7 and 19. Twenty-three cases stained for both antigens, whereas only 2 cases were negative for both cytokeratins. Twenty-two MPNSTs demonstrated immunoreactivity for S-100 protein, and 11 stained focally for AE1/AE3 or EMA. Two cases of MPNST stained for cytokeratin 7, and only 1 case stained for cytokeratin 19. No cases of MPNST stained for both cytokeratins. Antibodies to cytokeratins 7 and 19 are useful adjuncts for the separation of MSS from MPNST. The majority of MSSs stain for one or both of these antigens, whereas most MPNSTs, including those that are EMA- or AE1/AE3-positive, do not express these cytokeratin subsets.

Topics: Biomarkers, Tumor; Diagnosis, Differential; Humans; Immunoenzyme Techniques; Keratin-7; Keratins; Nerve Sheath Neoplasms; Sarcoma, Synovial; Soft Tissue Neoplasms

Epithelioid sarcoma (ES) is an aggressive soft-tissue malignant tumor generally arising in the distal extremities of young adults. The microscopic diagnosis of ES is often difficult because of its rarity and its possible confusion with other malignant tumors or even with benign granulomatous processes. Two cases of ES and a recurrence of one of these tumors, diagnosed by fine-needle aspiration biopsy (FNAB), are reported. Cytologic smears were quite similar in both cases including the relapse, showing single or loosely arranged groups of medium to large atypical cells. Single cells had well-defined eosinophilic cytoplasms and one or more atypical, eccentrically located nuclei, resulting in a plasmacytoid appearance. Nuclei had fine granular chromatin and one or two large nucleoli. The cells sometimes palisaded along the edges of necrotic material. The immunocytochemical stains showed diffuse cytoplasmic positivity for cytokeratins (CAM 5.2) and both cytoplasmic and cell membrane positivity for vimentin, while S-100 protein and HMB 45 immunostaining were negative, thus supporting the cytological diagnosis of ES, which was subsequently proven on the surgical samples. Diagn. Cytopathol. 1999;21:405-408.

Topics: Adult; Biopsy, Needle; Female; Humans; Immunohistochemistry; Keratins; Male; Middle Aged; Sarcoma; Soft Tissue Neoplasms

We report a case of synovial sarcoma with extensive myxoid change diagnosed by fine-needle aspiration. The patient is a 46-year-old woman who presented with a right paratibial mass. Aspiration cytology demonstrated a spindle cell neoplasm consistent with a synovial sarcoma but containing a prominent myxoid matrix. The clinical suspicion and cytologic diagnosis of a synovial sarcoma was confirmed by histologic and immunohistochemical findings. The cytologic differential diagnosis of spindle cell neoplasms with extensive myxoid change should be broadened to include synovial sarcoma.

Topics: Biomarkers, Tumor; Biopsy, Needle; Diagnosis, Differential; Female; Humans; Immunohistochemistry; Keratins; Middle Aged; Mucins; Sarcoma, Synovial; Soft Tissue Neoplasms

The clinicopathologic, immunohistochemical, and ultrastructural features of soft tissue angiosarcomas are not well defined. Eighty cases of angiosarcoma that involved the deep subcutis, skeletal muscle, retroperitoneum, mesentery, and mediastinum are reported. The lesions occurred in 50 male and 30 female patients who were 5-97 years of age; the peak incidence was in the seventh decade of life. A variety of associated conditions were documented in 20 of these cases, including a history of other neoplasms (some irradiated), synthetic vessel grafts, heritable conditions, and prior trauma or surgery. The angiosarcomas occurred in the extremities (n = 43 cases), trunk (n = 28), and the head and neck (n = 9) regions, with the thigh and the retroperitoneum being the most common sites. They often were characterized as enlarging, painful masses of several weeks' duration and were occasionally associated with acute hemorrhage, anemia, or a coagulopathy. The tumors measured 1-15 cm in diameter (median 5 cm) and frequently were hemorrhagic and multinodular. There was a wide morphologic spectrum within and between cases, including areas similar to cavernous and capillary hemangioma, Dabska tumor, spindle cell and epithelioid hemangioendothelioma, various spindle cell sarcomas, or carcinoma. Histologically, epithelioid angiosarcoma was the most frequently observed pattern; 70% of cases had epithelioid cells that were arranged in nests, clusters, papillae, and gaping vascular channels. Hemorrhage tended to obscure the diagnosis in several cases and often was associated with papillary endothelial hyperplasia-like areas. All 42 cases studied immunohistochemically stained at least focally for Factor VIII-related antigen, and nearly all stained strongly for vimentin, which accentuated the endothelial cells and vessel lumen formation. CD34 antigen was detected in 74% of cases, BNH9 in 72%, and cytokeratins in 35%. Epithelial membrane antigen, S-100 protein, and HMB45 were not detected. Fifty-five percent of the tumors had intracytoplasmic aggregates of laminin. Immunostains for alpha-smooth muscle actin demonstrated a prominent pericytic component in several tumors (24%). Ki67 immunostains with MIB1 indicated high proliferative activity (> or =10%) in 72% of cases. p53 immunoreactivity (>20% nuclear staining) was observed in 20% of cases. Ultrastructural studies performed on poorly differentiated areas of 12 cases showed groups of cells, which were frequently epithelioid, s

Topics: Actins; Adolescent; Adult; Aged; Aged, 80 and over; Biomarkers, Tumor; Child; Child, Preschool; Female; Hemangiosarcoma; Humans; Immunohistochemistry; Keratins; Male; Microscopy, Electron; Middle Aged; Prognosis; Soft Tissue Neoplasms; von Willebrand Factor

Topics: Diagnosis, Differential; Humans; Keratins; Mixed Tumor, Malignant; Myoepithelioma; S100 Proteins; Soft Tissue Neoplasms

We report the findings of 19 cases of a previously undescribed spindle cell tumor of soft tissues that resembles a low-grade fibromyxoid sarcoma but contains distinctive rosettelike structures. The tumors occurred principally as a painless, slowly growing, deeply situated mass of the proximal extremities in young to middle-aged adults (age range 14-65 years; mean 38). Although grossly circumscribed, the tumors had infiltrative borders microscopically and were composed of bland spindled cells situated in a hyalinized to myxoid stroma. The most characteristic feature of the tumor was scattered large rosettelike structures that often merged with serpinginous areas of dense hyalinization. The rosettes consisted of a central collagen core surrounded by a rim of rounded cells morphologically and immunophenotypically different from the cells of the spindled stroma. These cells expressed a number of antigens, including S-100 protein, neuron-specific enolase, and leu 22, in contrast to the stroma, which usually lacked these antigens. Of the 12 patients with available follow-up information, one patient treated with simple excision clinically developed local recurrence of the tumor 20 months after initial biopsy. No other recurrences were reported during the limited follow-up period, and no patient developed metastatic disease. However, the favorable prognosis of the patients in our series to date may relate to the limited follow-up period (approximately 3 years), as well as initial treatment by wide excision in nearly half of the patients. We regard the hyalinizing spindle cell tumor with giant rosettes as a distinctive type of low-grade fibroblastic tumor that with time may prove to behave similar to a low-grade fibromyxoid sarcoma and, hence, to represent an unusual variant thereof.

Topics: Actins; Adolescent; Adult; Aged; Antigens, CD; Desmin; Diagnosis, Differential; Female; Fibroma; Fibrosarcoma; Humans; Keratins; Male; Middle Aged; Neurilemmoma; Peripheral Nervous System Neoplasms; Retrospective Studies; S100 Proteins; Soft Tissue Neoplasms; Vimentin

Four soft tissue tumors corresponding with the previously reported parachordoma are described. Three of the patients were men, and one was a woman, and their ages ranged from 14 to 53 years (mean age, 29). The tumors were located either superficially or within muscle, and, in one case, involved a tendon. Histologically, the tumors displayed whorls, nests, and pseudoglandular cords of uniform polygonal cells with eosinophilic, vacuolated cytoplasm, in a focally myxoid stroma. Transitions were seen between fascicles of ovoid-spindled cells, with scanty cytoplasm in a fibrous stroma, and, in one case, whorls of bland spindly cells were also present. Electron microscopy of one case showed cells with short interdigitating microvilli and ill-defined junctions. The principal cells in all cases were positive for S100 protein, Leu-7, keratin (CAM5.2), and epithelial membrane antigen (EMA). All tumors were negative with antibody AE1 and with antibodies to cytokeratins CK7 and CK19. No tumor displayed immunoreactivity for carcinoembryonic antigen (CEA), muscle specific actin (MSA), smooth muscle actin (SMA), desmin, glial fibrillary acid protein (GFAP), CD31, or CD34. Parachordoma appears to be an entity with clinical and pathological differences from chordoma, which has a different cytokeratin profile, behaves in a more aggressive fashion, and can dedifferentiate. The differential diagnosis includes myxoid chondrosarcoma, myoepithelial cell tumor, ossifying fibromyxoid tumor, and chondroid lipoma.

Topics: Adolescent; Adult; CD57 Antigens; Chondrosarcoma; Chordoma; Diagnosis, Differential; Female; Humans; Immunoenzyme Techniques; Keratins; Male; Middle Aged; Mucin-1; S100 Proteins; Soft Tissue Neoplasms

Topics: Adolescent; Adult; Antibodies, Monoclonal; Female; Humans; Immunophenotyping; Keratins; Macrophages; Male; Receptors, Cytoadhesin; Sarcoma, Synovial; Soft Tissue Neoplasms; Synovial Membrane; Uridine Diphosphate Glucose Dehydrogenase

Seven of 24 soft tissue melanomas were shown to express keratins using antibodies CAM 5.2, LP34 and MNF116. No clinical or histological differences were seen in these seven cases when compared with the 17 keratin negative cases.

Topics: Adult; Biomarkers, Tumor; Case-Control Studies; Female; Humans; Immunohistochemistry; Keratins; Male; Sarcoma, Clear Cell; Soft Tissue Neoplasms

To compare the expression of S100 protein, alpha-smooth muscle actin (alpha-SMA) and keratin 19 in odontogenic myxomas and non-odontogenic myxoid lesions.. Formalin fixed, paraffin wax embedded tissue from seven odontogenic myxomas, three soft tissue myxomas, six hyperplastic myxoid dental follicles, two intramuscular myxomas, 12 cardiac myxomas, and seven normal dental follicles were examined immunocytochemically for S100 protein, alpha-SMA and cytokeratin 19 using the Streptavidin-biotin method.. A minority of odontogenic myxomas (three of seven) were positive for S100 and the staining was of moderate intensity and in all myxofibroblasts. Soft tissue myxomas, normal dental follicles, intramuscular myxomas, and most enlarged myxoid follicles were negative. In the cardiac myxomas the cells forming cords and islands were positive in approximately half (seven of 12), but the dispersed stellate myxoblasts were positive in only two cases. A population of cells in all the odontogenic myxomas and hyperplastic dental follicles contained alpha-SMA, but such cells were sparse in cardiac myxomas and present in only four cases. Cytokeratin 19 was present in odontogenic epithelium of odontogenic myxoma and follicles.. A minority of odontogenic myxomas, but not other oral myxoid lesions, may express S100 protein and this could cause difficulty distinguishing myxoma from myxoid nerve sheath tumours. Sparse myofibroblastic cells occurred in all types of myxoma tested. The epithelium sometimes found within jaw myxomas expresses cytokeratin 19 and this is consistent with an odontogenic origin.

Topics: Actins; Dental Sac; Heart Neoplasms; Humans; Keratins; Myxoma; Odontogenic Tumors; S100 Proteins; Soft Tissue Neoplasms

This article describes 11 cases of myxoid chondrosarcoma (MCS), with 10 arising in soft tissues and one developing in bone. Most of the tumors (six) were located in the lower extremities. Two lesions developed in the fingers, a previously unreported location for MCS. Four cases showed secondary bone destruction, which is a rare feature of this tumor. S100 protein was expressed by tumor cells in all the specimens. Four out of eight tumors studied by electron microscopy contained intracisternal microtubular structures. Two tumors showed areas of spindle cell proliferation that merged with the areas of typical myxoid pattern. The cells in these areas had fibroblastic/myofibroblastic features by electron microscopy and were found to express cytokeratin by immunohistochemistry. The concomitant expression of cytokeratin and S100 protein in the spindle cells suggests that they represent a less differentiated cartilaginous component with unusual features. The clinical significance of the presence of such spindle cell areas presently remains unknown. Although myxoid chondrosarcoma is a slow-growing tumor, it has a high potential for metastases. Four of 11 patients in this series developed metastases.

Topics: Adolescent; Adult; Aged; Bone Neoplasms; Chondrosarcoma; Endoplasmic Reticulum, Rough; Female; Fingers; Foot; Humans; Immunohistochemistry; Keratins; Male; Microscopy, Electron; Microtubules; Middle Aged; Radiography; Retrospective Studies; S100 Proteins; Soft Tissue Neoplasms

Primary subcutaneous leiomyosarcoma is a rare neoplasm composed of plump, elongated spindle cells arranged in interweaving fascicles.. Differential diagnosis might be facilitated by the use of immunohistochemistry.. A case of subcutaneous leiomyosarcoma was investigated histologically on paraffin-embedded tissue and immunohistochemistry was performed following standard procedures.. The case reported exhibited light microscopic features and an immunophenotype characteristic of leiomyosarcoma. However, the intermediate filament desmin could only be found on a small number of tumor cells.. Expression of these markers might vary considerably and immunoperoxidase stainings need to be carefully evaluated. Utilization of several antibodies directed against different desmin epitopes might be advantageous.

Topics: Aged; Desmin; Diagnosis, Differential; Female; Humans; Immunohistochemistry; Immunophenotyping; Keratins; Leiomyosarcoma; Soft Tissue Neoplasms; Thigh; Vimentin

Whether the peripheral ameloblastoma (PA) and intraoral basal cell carcinoma (BCC) are two different clinical entities or essentially the same lesion still remains unresolved. The immunophenotypes of neoplastic cells of peripheral and intraosseous ameloblastomas, ameloblastic carcinomas, and BCCs were studied using a panel of monoclonal/polyclonal antibodies and lectins. The major cytokeratins (CKs) of neoplastic cells of ameloblastomas were CKs 5 and 14, whereas co-expression of CKs 8, 18, and 19 was observed in the cells of the stellate reticulum-like areas. Metaplastic squamous and keratinizing cells found in follicular and acanthomatous variants of ameloblastomas expressed CKs 1 and 10, involucrin, and binding sites for the lectins Ulex europeaus agglutinin I and Helix pomatia agglutinin. beta 2-Microglobulin was uniformly negative in all cases of ameloblastomas and ameloblastic carcinomas studied. Cutaneous BCCs also demonstrated similar reactive patterns with the above-mentioned antigens. The most striking feature is the presence of a peritumorous band-like peanut agglutinin staining found in both BCCs and PAs but not in intraosseous ameloblastomas. This unique peanut agglutinin staining pattern of PA may be diagnostically useful for its histopathologic distinction from an intraosseous ameloblastoma that has infiltrated the soft tissue. The neoplastic cells of ameloblastomas express markers of less-differentiated epithelial cells. Despite differences in epithelial origins, PAs are tumors analogous to cutaneous BCCs.

Topics: Adolescent; Adult; Aged; Ameloblastoma; Antigens, Differentiation; beta 2-Microglobulin; Bone Neoplasms; Carcinoma, Basal Cell; Female; Humans; Immunoenzyme Techniques; Keratins; Lectins; Male; Middle Aged; Protein Precursors; Receptors, Mitogen; Skin Neoplasms; Soft Tissue Neoplasms

Virtually all reported cases of epithelioid sarcoma have been vimentin rich, and the coexpression of vimentin and keratin is considered a characteristic immunophenotype in these tumors. We report three cases of soft tissue tumors with histologic and clinical features consistent with epithelioid sarcoma, all of which failed to immunoreact by standard immunohistochemistry for vimentin using two different monoclonal antibodies. Antigen retrieval demonstrated focal vimentin staining in one case, whereas the other two remained negative. An extensive panel of immunohistochemical stains revealed strong diffuse staining with keratin and epithelial membrane antigen in all three cases as well as patchy membrane staining with an antibody to CD34. CD34 positivity is commonly seen in epithelioid sarcoma, but it is very rarely found in carcinomas. We conclude that these cases represent a unique immunophenotypic variant of epithelioid sarcoma that can be immunohistochemically confirmed, despite the lack of identifiable vimentin, by their immunoreactivity for keratin and CD34.

Topics: Adult; Antigens, CD; Antigens, CD34; Cytoplasm; Diagnostic Errors; Eosinophils; Female; Humans; Immunohistochemistry; Keratins; Male; Membrane Glycoproteins; Middle Aged; Mucin-1; Sarcoma; Soft Tissue Neoplasms; Vimentin

An ulcerated tumour was removed by a Whipple's operation from the descending part of the duodenum of a 38-year-old male. The tumour cells were mainly spindle-shaped, arranged in nests and had very prominent nucleoli. A few cells contained melanin and melanosomes. Immunoreactivity for S-100 protein and focally for HMB-45 was observed. These features are diagnostic for clear cell sarcoma of tendons and aponeuroses. Because no other primary tumour could be found and the search for similar cases from the literature was unsuccessful, we believe that this tumour is the first reported clear cell sarcoma in a visceral location.

Topics: Adult; Desmin; Duodenal Neoplasms; Duodenum; Humans; Immunohistochemistry; Keratins; Male; Melanoma; S100 Proteins; Sarcoma; Soft Tissue Neoplasms; Tendons; Tomography, X-Ray Computed; Ultrasonography; Vimentin

Eight epithelioid sarcomas (ES) were studied by electron microscopy, immunohistochemistry, and DNA flow cytometry. Ultrastructurally, the tumour cells showed desmosome-like intercellular junctions and numerous microvilli, in addition to whorled arrangements of intermediate filaments. Tumour cells were positive for epithelial membrane antigen, cytokeratin, and vimentin, and negative for carcinoembryonic antigen and desmin. All seven cases examined by flow cytometry showed diploid or hyperploid (near diploid) DNA content. This seems to correspond to the relatively long clinical course and low-grade malignant nature of ES. Although the histogenesis of ES is still uncertain, the results of this study suggest that it is a tumour of primitive mesenchymal cells with the capacity to show epithelial differentiation.

Topics: Adult; CD4-CD8 Ratio; DNA, Neoplasm; Female; Flow Cytometry; Humans; Immunohistochemistry; Intercellular Junctions; Keratins; Male; Membrane Glycoproteins; Microscopy, Electron; Microvilli; Middle Aged; Mucin-1; Ploidies; Sarcoma; Soft Tissue Neoplasms; Vimentin

An unusual and, apparently, hitherto undescribed congenital lesion of the scalp which proved to be heterotopic meningothelial tissue is reported, and its clinical, morphological, and theoretical implications are reviewed. A 14-month-old male infant exhibited a soft tissue lesion on the midline of the parietal scalp since birth. The lesion had grown in size since birth. Histological examination showed an admixture of mature adipose tissue, bands consisting of bundles and small nodules of dense collagen, both enclosed and bordered by rests and strands of meningothelial cells. A network of vessel-like channels lined by plump hyperchromatic cells with spindle-shaped nuclei and occasionally multinucleated giant cells was one of the prominent features. Immunohistochemically, these cells were positive for vimentin, but staining was negative for EMA and all other antibodies tested. A fibrocollagenous stalk via bony defect showed no arachnoid cell rests. The authors believe that the herein described lesion and the hamartoma of the scalp described by Suster and Rosai (1990) may represent varying morphological expressions of a pathogenetically related process. Precautions appropriate to the possibility of intracranial extension must be taken at the time of surgery.

Topics: Antigens, Neoplasm; Collagen; Hamartoma; Humans; Immunohistochemistry; Infant; Keratins; Male; Meninges; Scalp; Skin Neoplasms; Soft Tissue Neoplasms

Routine paraffin-embedded sections from synovial sarcomas in 70 patients were stained immunohistochemically with monoclonal anti-cytokeratin antibody and serum against mesothelial cells. Positive reactions occurred in the epithelioid cells of biphasic tumors only. On the ground of the reaction with anti-mesothelial serum a hypothetical scheme of cell differentiation in synovial sarcoma was set up.

Topics: Antibodies, Monoclonal; Cell Differentiation; Diagnosis, Differential; Epithelium; Humans; Immune Sera; Immunohistochemistry; Keratins; Mesothelioma; Paraffin Embedding; Sarcoma, Synovial; Soft Tissue Neoplasms; Staining and Labeling

Five cases of a previously undescribed variant of epithelioid sarcoma are presented. This variant differs from the usual lesion in its absence of the typical necrobiotic nodular epithelioid pattern. It is instead composed of deceptively bland fibrohistiocytic and myoid cells arranged in a fibroma-like or dermatofibroma-like pattern with an affinity for osseous involvement. The clinical presentation, ultrastructural features, and presence of vimentin and low molecular weight keratin within the tumor cells justifies their designation as an epithelioid sarcoma variant.

Topics: Adolescent; Adult; Bone Neoplasms; Calcaneus; Diagnosis, Differential; Female; Femoral Neoplasms; Fibroma; Fingers; Histiocytoma, Benign Fibrous; Humans; Humerus; Keratins; Male; Neoplasm Recurrence, Local; Neoplasms, Multiple Primary; Sarcoma; Skin Neoplasms; Soft Tissue Neoplasms; Thigh; Tibia; Toes; Ulna; Vimentin

The presence of individual keratin polypeptides and desmoplakins was immunohistochemically studied in 25 spindle cell sarcomas of different types using acetone-fixed frozen sections. Results revealed that keratins 8 and 18 were present in a high number of tumors: 9 of 9 synovial sarcomas, 5 of 7 leiomyosarcomas, 5 of 5 malignant schwannomas, and 1 of 4 undifferentiated spindle cell sarcomas. In addition to keratins 8 and 18, the glandular component of synovial sarcoma showed prominent reactivity with antibodies to keratins 7 and 19. Also the glandular epithelial cells in synovial sarcoma showed desmoplakin immunoreactivity preferentially in a luminal distribution, but desmoplakin was absent in other spindle cell sarcomas. Furthermore keratin 13 was seen focally in 4 of 9 synovial sarcomas. In contrast, keratins 7, 13, and 19 were practically absent in leiomyosarcomas, malignant schwannomas, and undifferentiated spindle cell sarcomas. The widespread presence of keratins 8 and 18 in various spindle cell sarcomas may reflect aberrant keratin expression in mesenchymal cells, previously described in cultured transformed fibroblasts. The presence of keratins 7 and 19 and desmoplakin is highly associated with morphologically observable epithelial differentiation restricted to synovial sarcoma among spindle cell sarcomas.

Topics: Cytoskeletal Proteins; Desmoplakins; Desmosomes; Humans; Keratins; Leiomyosarcoma; Neurilemmoma; Peptides; Peripheral Nervous System Neoplasms; Sarcoma; Sarcoma, Synovial; Soft Tissue Neoplasms

Twenty-six cases of malignant soft tissue tumors with features similar to renal rhabdoid tumors were identified among approximately 3,000 childhood sarcomas entered on Intergroup Rhabdomyosarcoma Studies I-III. The tumors consisted of polygonal cells with vesicular nuclei and prominent nucleoli and cytoplasmic intermediate filament inclusions as identified by electron microscopy and immunohistochemistry. The growth pattern was predominantly solid or solid-trabecular. Immunohistochemistry showed vimentin, wide spectrum keratin, and epithelial membrane antigen to be the most consistent antigenic phenotypes. Eleven patients were infants less than 1 year of age. The tumors affected predominantly soft tissues of proximal extremities, trunk, and retroperitoneum/pelvis/abdomen. Nineteen patients died within 1 to 82 months (median, 6 months) from the start of treatment. Five patients have survived the disease for 2 to 13 years. When compared with the survival analysis of 991 Intergroup Rhabdomyosarcoma Study II patients, it was obvious that this group of tumors fares very poorly (P less than .001). The tumor belongs to the group of soft tissue neoplasms showing mesenchymal and subtle epithelial differentiation, similar to epithelioid sarcoma. Because of its identifiable histology, site and age distribution, and poor outcome, it warrants a status as an independent entity.

Topics: Adolescent; Antigens, Neoplasm; Brain Neoplasms; Child; Child, Preschool; Female; Humans; Infant; Keratins; Kidney Neoplasms; Male; Membrane Glycoproteins; Mucin-1; Rhabdomyosarcoma; Soft Tissue Neoplasms; Vimentin

We report eight cases of epithelioid angiosarcoma arising in deep, usually intramuscular soft tissue. All the patients were men (mean age, 58). All the lesions arose in a limb or limb girdle. Cardinal morphologic features were the diffuse, sheetlike growth pattern, with only focally apparent vascular differentiation, and epithelioid tumor cells with a degree of intracytoplasmic vacuolation/lumen formation. Immunohistochemically, all eight cases coexpressed keratin as well as endothelial markers. In three cases, endothelial differentiation was confirmed ultrastructurally. Clinically, deep-seated epithelioid angiosarcomas are high-grade neoplasms that rapidly develop metastases. These findings expand the range of recognized epithelioid endothelial tumors and provide further evidence of keratin expression by such lesions. The presence of intracytoplasmic lumina/vacuoles (sometimes containing red blood cells) combined with the characteristic reticulin pattern and striking positivity for Factor VIII-RAg provide the clearest means of distinction from an epithelial metastasis.

Topics: Adult; Aged; Diagnosis, Differential; Hemangiosarcoma; Humans; Immunohistochemistry; Keratins; Male; Microscopy, Electron; Middle Aged; Soft Tissue Neoplasms; von Willebrand Factor

Topics: Artifacts; Humans; Immunochemistry; Keratins; Sarcoma; Soft Tissue Neoplasms

The clinicopathologic, ultrastructural, and immunohistochemical features of six cases of extraskeletal myxoid chondrosarcoma are described. Light microscopic examination disclosed a lobulated neoplasm consisting of cells that tended to be round or polygonal with plenty of eosinophilic cytoplasm. The tumor cells were arranged in strands and small nests surrounded by abundant myxoid extracellular matrix. Ultrastructurally, these tumor cells displayed the signs of chondroblastic differentiation. The cytoplasm contained numerous rough endoplasmic reticulum, mitochondria and scattered glycogen granules. The intercellular matrix showed amorphous material and electronic dense and fine granules. The tumor cells in all these six cases showed diffuse immunostaining for S-100 protein but were negative for keratin. The data obtained tend to support the chondroblastic origin of this tumor.

Topics: Adult; Aged; Chondrosarcoma; Female; Humans; Keratins; Male; Middle Aged; S100 Proteins; Soft Tissue Neoplasms

Two hundred soft tissue sarcomas, accrued consecutively over a 4-year period, were examined by light and electronmicroscopy and by routine immunohistochemistry. The commonest tumour type was malignant fibrous histiocytoma. Fibrosarcoma, composed only of fibroblasts, was diagnosed in only one case; three others, composed also of myofibroblasts, could be regarded as fibrosarcomas or myofibrosarcomas. Immunohistochemistry was of most value in the diagnosis of rhabdomyosarcoma, leiomyosarcoma, malignant peripheral nerve sheath tumour of Schwann cell type and epithelioid sarcoma. Electronmicroscopy was of most use for the diagnosis of malignant peripheral nerve sheath tumour of perineurial cell type and marker-negative monophasic synovial sarcoma, and for confirming malignant fibrous histiocytoma. Fifteen of 19 marker-negative spindle cell tumours (79%) were diagnosable by electronmicroscopy. A combination of techniques resulted in a specific diagnosis in 193 cases (96.5%). The routine use of electronmicroscopy in sarcoma diagnosis can improve accuracy of diagnosis, establish the true frequency of marker-positivity for each ultrastructurally confirmed tumour type and minimise the number of unclassifiable cases.

Topics: Biomarkers, Tumor; Diagnostic Errors; Evaluation Studies as Topic; Humans; Immunohistochemistry; Keratins; Microscopy, Electron; Sarcoma; Soft Tissue Neoplasms

Topics: Biomarkers, Tumor; Cell Transformation, Neoplastic; Child; Connective Tissue; Humans; Immunoenzyme Techniques; Keratins; Phosphopyruvate Hydratase; Rhabdomyosarcoma; S100 Proteins; Soft Tissue Neoplasms

The paper presents immunofluorescence findings on the distribution of medium-sized vimentinic and cytokeratinic filaments in the cells of epithelioid sarcoma. Two morphologically different types of tumor cells have been shown to be distinguished by the pattern of their filament expression: fusiform fibroblastoid cells contain vimentin (a mesenchymal type of differentiation), but there is a coexpression of cytokeratin and vimentin (an epithelial type) in the so-called epithelioid cells. Double mesenchymal-and-epithelial differentiation of the cells makes it possible to suppose that this tumor is of mesodermal rather than mesenchymal origin as is generally accepted. The features found in the distribution of medium-sized filaments in the epithelioid sarcoma may be useful in the practical differential diagnosis of this tumor as compared to numerous morphologically similar neoplasms.

Topics: Adolescent; Adult; Child; Female; Fluorescent Antibody Technique; Humans; Keratins; Male; Middle Aged; Sarcoma; Soft Tissue Neoplasms; Vimentin

We describe 59 cases of a microscopically unique neoplasm that has not been previously reported. The tumor almost exclusively affected adults (range 14-79 years) and had a male predominance (38 men and 21 women). It presented in most cases as a small, painless, well-circumscribed mass (median, 4 cm) in subcutis or muscle. It occurred chiefly in the upper and lower extremities (40 cases) and less frequently in the trunk (11 cases) and the head and neck region (eight cases). Microscopically, the tumor was partly lobulated and composed of small, round cells that had vesicular nuclei and indistinct cytoplasm. Typically, the cells were arranged in a cord- or nestlike pattern within a myxoid matrix that frequently showed transitions toward hyaline fibrosis and focal osteoid formation. In about two-thirds of the cases, the cells contained immunoreactive S-100 protein. An additional typical feature, seen in 48 (81%) of the 59 cases, was the presence of an incomplete shell of mature bone in the capsular region of the tumor. Follow-up information, available in 41 cases, revealed that 11 patients (27%) experienced one or more recurrences. One patient with three recurrences developed a second tumor in the opposite thigh, presumably a metastasis. None of the patients died of the tumor, but three died of causes unrelated to the disease. Although the histogenesis is uncertain, cartilaginous or neural origin seem to be most likely. Until this issue is resolved, we prefer the descriptive and less committal designation of "ossifying fibromyxoid tumor of soft parts."

Topics: Adolescent; Adult; Aged; Chondroma; Chondrosarcoma; Female; Fibroma; Glial Fibrillary Acidic Protein; Humans; Immunohistochemistry; Keratins; Male; Microscopy, Electron; Middle Aged; Neoplasm Recurrence, Local; Ossification, Heterotopic; S100 Proteins; Soft Tissue Neoplasms

An extrarenal malignant rhabdoid tumor arising from soft parts in the prepubic region of a 37-year-old man is described. This case appears to be unusual with regard to its location and age at onset. To our knowledge, the patient is the oldest recorded in whom such a lesion has arisen. Histologically, the tumor consisted of an admixture of polygonal and elongated cells with abundant eosinophilic cytoplasm frequently containing hyaline-like globules. Ultrastructurally, these cytoplasmic inclusions were compatible with intermediate filaments. Immunohistochemical staining disclosed keratin (non-squamous epithelial type) and epithelial membrane antigen positivity. These characteristic features were identical to malignant rhabdoid tumor of the kidney seen in infants and young children. This extrarenal malignant rhabdoid tumor showed an aggressive clinical course, although its exact histogenesis was unclear.

Topics: Adult; Cell Nucleus; Cytoplasm; Humans; Immunoenzyme Techniques; Intermediate Filaments; Keratins; Male; Membrane Glycoproteins; Microscopy, Electron; Mucin-1; Pubic Bone; Rhabdomyosarcoma; Soft Tissue Neoplasms

The present report is a light- and electron-microscopic and immunohistochemical study of 7 cases of epithelioid sarcoma. Formalin-fixed and paraffin-embedded material and in one case ethanol-fixed material from the tumors as well as control tissues were used for the immunohistochemical analysis. A positive reaction for cytokeratins was observed in all 7 tumors when using 3 different polyclonal antibodies and 1 of 3 monoclonal antibodies. All tumors were positively stained with monoclonal antibodies against the epithelial membrane antigen (EMA) and all except one with monoclonal antibodies against the human milk fat globule (HMFG 1 and 2). In all tumors there was a positive reaction for actin and vimentin, using monoclonal antibodies. Ultrastructurally the tumor cells were characterized by pinocytic vesicles, cytoplasmic projections surrounding lumen-like slits, desmosome-like cell junctions and abundant thin and intermediate filaments, sometimes forming condensed bundles and tonofilament-like structures. In one case there were numerous dense cytoplasmic bodies, up to 800 nm in diameter, apparently formed by condensed intermediated filaments. The tumor cells of epithelioid sarcoma share morphologic features and immunohistochemical properties with epithelial cells, which however does not exclude the possibility of a mesenchymal origin.

Topics: Actins; Adult; Antibodies, Monoclonal; Antigens; Cytoskeleton; Female; Humans; Immunohistochemistry; Inclusion Bodies; Keratins; Male; Membrane Glycoproteins; Microscopy, Electron; Middle Aged; Mucin-1; Sarcoma; Soft Tissue Neoplasms; Vimentin

Five cases of epithelioid sarcoma are reported, of which four were studied by immunohistochemistry and one by electron microscopy. Immunohistochemically, the results of cytokeratin showed that these four cases were positive to different degrees by polyclonal cytokeratin and three out of four revealed positive results with low molecular weight cytokeratin monoclonal antibody. Two cases were positive with carcinoembryonic antigen and the other two were negative. The immunohistochemical stain was helpful for differential diagnosis from other sarcomas, such as malignant fibrous histiocytoma and rhabdomyosarcoma. By electron microscopy, tumor cells could be divided into light and dark cells which possessed more or less cell organelles, intermediate microfilaments in the cytoplasm and numerous pinocytic vesicles lying along the cell membrane. The occasional presence of poorly developed desmosomes or the absence of tonofibril bundles and glandular structures can rule out the diagnosis of carcinoma. One of these cases was originally diagnosed as metastatic carcinoma to the skin by light microscopy, which was refuted by electron microscopy, and the keratin positive reaction by immunohistochemistry was helpful for the diagnosis of epithelioid sarcoma. Therefore, the authors suggest that immunohistochemical and electron microscopic studies be used for diagnosing difficult cases of epithelioid sarcoma. From our observation, we consider that the cells of epithelioid sarcoma may derive from undifferentiated mesenchymal cells possessing the potentials of differentiating into synovioblasts, histiocytes or fibroblasts.

Topics: Adult; Carcinoembryonic Antigen; Child, Preschool; Female; Humans; Immunohistochemistry; Keratins; Male; Middle Aged; Sarcoma; Soft Tissue Neoplasms

The relationship of "chordoid sarcoma" (CS) to chordoma and myxoid chondrosarcoma has been debated for several years. In order to reassess this issue, we studied 5 CS, 5 chordomas, and 3 skeletal myxoid chondrosarcomas ultrastructurally and immunohistochemically. By electron microscopy, CS demonstrated smooth cellular outlines, macular intercellular junctions, and cytoplasmic inclusions of matrix-like material. Chordomas displayed a closely similar fine structural appearance, but in addition contained small, membrane-bound, glycogen-containing inclusions. Skeletal myxoid chondrosarcomas resembled CS, except that the former lesions had spiculated cell membranes and lacked intercellular junctions. Immunohistochemically, all CS cases expressed vimentin and lacked cytokeratin (CK). Leu 7 and S100 protein were seen in four cases each of CS, and three of these tumors demonstrated diffuse or focal reactivity for epithelial membrane antigen (EMA). Similar phenotypic features were seen in chordomas, except that all of them stained diffusely for CK, as well as EMA. Skeletal myxoid chondrosarcomas expressed vimentin, S100, and Leu 7 uniformly, but were devoid of epithelial markers. In aggregate, these data support the classification of "chordoid sarcoma" as a form of chondrosarcoma, but reveal that it may exhibit an "epithelial" antigen in some cases.

Topics: Adult; Aged; Aged, 80 and over; Antigens, Neoplasm; Bone Neoplasms; Child, Preschool; Chondrosarcoma; Chordoma; Female; Humans; Immunoenzyme Techniques; Infant; Keratins; Male; Membrane Glycoproteins; Middle Aged; Mucin-1; S100 Proteins; Soft Tissue Neoplasms; Vimentin

Formalin-fixed histologic and acetone-fixed cytologic preparations from 87 surgically removed subcutaneous and soft tissue canine tumors were examined for immunoreactivity to cytokeratin, desmin, and vimentin. The avidin-biotin complex (ABC) technique demonstrated immunoreactivity in both preparations, but the intensity and specificity of the reactions were dependent on the primary antibody. Polyclonal antibodies to cytokeratin were more consistent in immunoreactivity than were polyclonal desmin or vimentin antibodies. The monoclonal antibody proved more satisfactory for demonstrating vimentin than the polyclonal antibody. Greater dilutions of primary antibodies may be used on cytologic preparations than on histologic sections. Evaluation of cytologic preparations may be inconclusive due to background staining, scant cellularity, or poor cytoplasmic preservation.

Topics: Animals; Antibody Specificity; Avidin; Biotin; Desmin; Dog Diseases; Dogs; Immunoenzyme Techniques; Intermediate Filament Proteins; Keratins; Predictive Value of Tests; Prospective Studies; Skin Neoplasms; Soft Tissue Neoplasms; Vimentin

Topics: Basement Membrane; Carcinosarcoma; Connective Tissue; Humans; Intercellular Junctions; Keratins; Microscopy, Electron; Neoplasm Proteins; Sarcoma, Synovial; Soft Tissue Neoplasms

Seven cases of synovial sarcoma (SS), two with biphasic and five with monophasic histology, were studied immunohistochemically using monoclonal antibodies to intermediate filaments, keratin, and vimentin. Slender spindle cells and plump cells were constant components of all the tumors. Epithelioid cells were present only in biphasic SS. Epithelioid cells and plump cells were positively stained by both keratin and vimentin. Slender spindle cells were stained positive for vimentin and negative for keratin. Staining manner of each cell type was similar irrespective of monophasic or biphasic pattern. Present immunohistochemical studies suggested that monophasic or biphasic patterns in SS should be regarded as a different expression of the same disease. In addition, immunohistochemistry proved to be a useful tool to detect plump cells which were difficult to find on routine staining.

Topics: Adolescent; Adult; Female; Foot; Hand; Humans; Immunoenzyme Techniques; Joint Diseases; Keratins; Knee Joint; Male; Sarcoma, Synovial; Soft Tissue Neoplasms; Vimentin

Topics: Epithelium; Histocytochemistry; Humans; Keratins; Membrane Proteins; Mucin-1; Sarcoma; Soft Tissue Neoplasms

We report the occurrence of rhabdoid cells in several specified soft tissue sarcomas of round cell variety. The rhabdoid cells had an acidophilic cytoplasm containing a globular perinuclear inclusion and were characterised ultrastructurally by the presence of aggregates of 10 nm intermediate filaments. These filaments contained both cytokeratin and vimentin, as demonstrated immunohistochemically. Extensive sampling of soft tissue sarcomas revealed the presence of such cells in different types of soft tissue round cell sarcomas as follows: 12 of 13 cases of epithelioid sarcomas, 8 of 13 synovial sarcomas (composed predominantly of round cells), 6 of 20 extraskeletal myxoid chondrosarcomas and 4 of 4 round celled malignant mesotheliomas. We wish to stress that the appearance of rhabdoid cells is not a monopoly of one particular type of tumour.

Topics: Cell Aggregation; Histocytochemistry; Humans; Inclusion Bodies; Keratins; Sarcoma; Soft Tissue Neoplasms; Vimentin

Nineteen synovial sarcomas, six biphasic and 13 monophasic tumors, were examined by light and electron microscopy and immunohistochemically for the presence of the epithelial markers keratin and epithelial membrane antigen (EMA). Ultrastructurally, intercellular spaces with processes are present to varying degrees in the spindle cell component of all synovial sarcomas, and junctional specializations occur in most cases. Tumors of the two types differ in their content of external (basal) lamina, which encloses the epithelial component of all biphasic tumors and is detectable in the spindle cell component of two thirds of them, but is absent from the majority of monophasic tumors. Keratin and EMA were demonstrated in both components of all six biphasic tumors. Of the 13 monophasic tumors, keratin was present in nine, EMA in eight, and at least one epithelial marker in ten. Synovial sarcoma is regarded as a distinctive soft tissue tumor with variable epithelial-like differentiation. The use of electron microscopy can increase the specificity of immunohistochemical studies of soft tissue sarcomas and allow more accurate differentiation of monophasic synovial sarcoma from other spindle cell tumors, particularly those that do not express markers.

Topics: Epithelium; Histocytochemistry; Humans; Immunochemistry; Joint Diseases; Keratins; Membrane Proteins; Microscopy, Electron; Mucin-1; Sarcoma; Soft Tissue Neoplasms; Synovial Membrane

Intermediate-sized filaments have been noted in epithelioid sarcoma by previous investigators, two of whom have reported that the filaments represent vimentin. We utilized polyclonal antibodies directed against keratin and immunoperoxidase techniques (PAP) to stain 32 of the more than 300 cases accumulated at the AFIP . All of our material was formalin-fixed, paraffin-embedded. Seventy-five percent of our cases (24/32) showed positive immunoreactivity, a feature that may be of diagnostic help in distinguishing epithelioid sarcoma from modular fasciitis, benign and malignant fibrous histiocytoma, malignant melanoma, and necrotizing granuloma. In these cases, the reaction was enhanced using predigestion with trypsin. The immunoreactivity varied from tumor to tumor, perhaps due to formalin fixation. Since synovial sarcoma and mesothelioma may also be cytokeratin-positive, our findings indicate that keratin immunoreactivity is not confined to epithelial tumors and may also occur in neoplasms traditionally regarded as mesenchymal.

Topics: Adolescent; Aged; Cytoskeleton; Female; Histocytochemistry; Humans; Immunoenzyme Techniques; Keratins; Male; Sarcoma; Soft Tissue Neoplasms

For an evaluation of the putative histogenetic relationship of synovia and synovial sarcomas, normal synovia, villonodular synovitis, and synovial sarcomas were compared for their patterns of expression of intermediate filaments of keratin and vimentin type and epithelial membrane antigen and for lectin binding sites. The lining cells in both normal synovia and villonodular synovitis reacted with anti-vimentin antibodies, but not with antibodies to different types of keratins or epithelial membrane antigen. The cleft-lining cells in synovial sarcoma, on the other hand, showed only keratin positivity, and epithelial membrane antigen could also be detected in these cells. Nonneoplastic synovial lining cells bound peanut agglutinin (PNA), Ricinus communis agglutinin (RCA), soybean agglutinin (SBA), concanavalin A (Con A), and wheat germ agglutinin (WGA) conjugates, but not Ulex europaeus I lectin (UEA I). In contrast, the epithelial-like cleft lining cells in synovial sarcomas showed an apical cytoplasmic binding of PNA, UEA I, RCA, and SBA, and binding of WGA to the whole cytoplasm but did not bind Con A. The distinct differences between synovial lining cells and synovial sarcoma cells speak against synovial cell features in synovial sarcoma. These results indicate that synovial sarcoma is a carcinosarcomalike tumor with true epithelial differentiation, and the term "synovial sarcoma" apparently is a misnomer that should be abandoned.

Topics: Antibodies; Antigens; Binding Sites; Cytoskeleton; Humans; Immunoenzyme Techniques; Keratins; Membrane Proteins; Microscopy, Fluorescence; Mucin-1; Receptors, Mitogen; Sarcoma, Synovial; Soft Tissue Neoplasms; Synovial Membrane; Synovitis, Pigmented Villonodular; Terminology as Topic; Vimentin

Monospecific antibodies and indirect immunofluorescence microscopy were used to investigate the presence of cytoskeletal intermediate filaments of the keratin, vimentin and desmin types in 43 soft-tissue sarcomas. The results showed that vimentin was present in the neoplastic cells of all types of soft-tissue sarcomas studied, whereas keratin was absent, the only exception being the epithelial-like cells in biphasic synovial sarcoma. The presence of desmin was confined to leiomyosarcomas and rhabdomyosarcomas, which usually showed desminpositivity. In addition, malignant fibrous histiocytomas occasionally displayed some desmin-positive cells. Thus, determination of intermediate filaments is of aid in the histogenetical diagnosis of tumors, because keratin-positivity largely excludes the possibility of a sarcoma, and desmin-positivity aids in recognizing leiomyosarcomas and rhabdomyosarcomas.

Topics: Desmin; Humans; Intermediate Filament Proteins; Keratins; Sarcoma; Soft Tissue Neoplasms; Vimentin