bromochloroacetic-acid and Neurilemmoma

We report a case of microcystic/reticular schwannoma of the proximal sigmoid colon in a 61-year-old man. A 12-mm polyp was detected while the patient was undergoing screening for colorectal neoplasm. This rare variant of schwannoma was initially described in 2008 and shows a predilection for the visceral organs, predominantly the gastrointestinal tract. We also review 11 other reported cases of microcystic/reticular schwannomas in the gastrointestinal tract. Unlike conventional gastrointestinal schwannomas, which are more common in the stomach, this variant appears to be more common in the large intestine. Histologic examination of this polyp showed predominant lipoblast-like vacuolated cells within a myxoid stroma with focal spindle cell areas. Features suggestive of malignancy, like nuclear pleomorphism, mitosis, or necrosis, were absent. Immunohistochemistry for S100 protein showed strong nuclear and cytoplasmic positivity, whereas cytokeratin and CD117 stains were negative. It is important to entertain microcystic/reticular schwannoma in the differential diagnosis of a signet ring cell adenocarcinoma or a myxoid gastrointestinal stromal tumor, particularly on small biopsy specimens.

Topics: Calgranulin A; Carcinoma, Signet Ring Cell; Colonic Neoplasms; Diagnosis, Differential; Gastrointestinal Stromal Tumors; Humans; Immunohistochemistry; Keratins; Male; Microscopy, Electron, Transmission; Middle Aged; Neurilemmoma; Proto-Oncogene Proteins c-kit

Miscellaneous primary tumors of the uterine cervix are rare. Markers which can be utilized to detect these tumors are very few and in most cases, have not been clinically validated. The information provided in this article will help in developing strategies to discover novel markers and initiate translational research in this ignored area. Based on the reported studies, cytokeratin markers are common in many tumors and few of these rare cancers demonstrate human papilloma-virus (HPV) and Epstein Bar virus (EBV) infection. Due to the very low prevalence of these tumors, epidemiological studies have not been conducted and the etiology of these tumors is largely unknown.

Topics: Biomarkers, Tumor; Carcinoma; Cell Transformation, Neoplastic; Female; Humans; Immunohistochemistry; Keratins; Lipoma; Melanoma; Neurilemmoma; Rare Diseases; Sarcoma; Uterine Cervical Neoplasms

The authors present a case of clear cell sarcoma (CCS) in which the tumor originated in the S-1 nerve root and had been previously diagnosed as psammomatous melanotic schwannoma (PMS). This is the third case of a spinal nerve root origin for CCS reported in the English-language literature. The similar histogenesis of CCS and malignant melanoma supports the hypothesis that biological agents or immunotherapy are potentially important areas of investigation. The patient underwent S1-3 laminectomy and gross-total resection of the mass lesion. The border of the resection was extended 1 cm distal to the tumor margin. The postoperative period was uneventful. The new histopathological diagnosis was CCS (malignant melanoma of soft tissue). Despite total resection, the patient returned with disseminated disease at the 18-month follow-up visit. His follow-up magnetic resonance image of the lumbar spine revealed sacral L5-S3 involvement of the vertebral bodies along with disseminated cauda equina seeding. A CCS originating from peripheral nerves is quite rare. The histopathological and immunohistochemical appearance of CCSs resembles those of PMSs. Surgery should be the first choice of treatment.

Topics: Adolescent; Adult; Antigens, Neoplasm; Biomarkers, Tumor; Breast Neoplasms; Diagnosis, Differential; Diagnostic Errors; Female; Fibroadenoma; Humans; Keratins; Male; Melanins; Melanoma-Specific Antigens; Neoplasm Invasiveness; Neoplasm Proteins; Neoplasm Recurrence, Local; Neoplasms, Multiple Primary; Neoplastic Syndromes, Hereditary; Nerve Sheath Neoplasms; Neurilemmoma; Peripheral Nervous System Neoplasms; Pigmentation Disorders; Prognosis; S100 Proteins; Sacrococcygeal Region; Sarcoma, Clear Cell; Spinal Nerve Roots; Syndrome; Vimentin

To gain insight into the pathogenesis of neurofibromatosis type 2 (NF2) by investigating the ocular manifestations of this disease.. Using standard histologic techniques, immunohistochemistry, and electron microscopy, we described the ocular pathologic findings of a 34-year-old woman who died from complications of NF2.. We identified 3 types of NF2-associated lesions: juvenile posterior subcapsular cataracts, epiretinal membranes, and an intrascleral schwannoma.. Our analysis indicated that dysplastic lens cells accumulate just anterior to the posterior lens capsule in juvenile posterior subcapsular cataracts and that dysplastic Müller cells may be a major component of NF2-associated epiretinal membranes. Clinical Relevance Our findings suggest that a subset of glial cells with epithelial features (Schwann cells, ependymal cells, and Müller cells) may be particularly sensitive to loss of the NF2 gene. Understanding the molecular basis for this sensitivity may lead to novel strategies for treating NF2.

Topics: Adult; Cataract; Epiretinal Membrane; Eye Neoplasms; Fatal Outcome; Female; Glial Fibrillary Acidic Protein; Humans; Immunoenzyme Techniques; Keratins; Mucin-1; Neurilemmoma; Neurofibromatosis 2; S100 Proteins; Scleral Diseases

Schwannomas have been variably observed to be glial fibrillary acid protein (GFAP) and occasionally keratin positive, with antibodies reacting with multiple keratins (pankeratins, keratin cocktail (CK), but specific keratin polypeptides (K) have not been examined for in schwannoma. Since we observed CK positivity in retroperitoneal schwannomas, we wanted to study a large group of retroperitoneal and peripheral schwannomas with GFAP, CK and Ks to explore the frequency and biologic background of this finding. We immunohistochemically evaluated a large number of retroperitoneal (n=115) and peripheral schwannomas (n=22) for GFAP, 16 individual K and AE1/AE3 keratin cocktail. The great majority (104/115, 90%) of retroperitoneal schwannomas were positive for GFAP, and 72/104 (69%) cases were positive for AE1/AE3, often extensively. Both markers highlighted the cellular Antoni A areas, particularly adjacent to the capsule, myxoid or degenerative areas, and perivascularly. Most cases 87/104 (84%) stained for both AE1/AE3 and GFAP at least focally. No tumors stained for keratins that were GFAP negative. None of the immunostains for individual K showed positivity comparable to that obtained with AE1/AE3 CK. However, 62% were focally positive for high molecular weight K1 and 8/61 (13%) for K7. None of the retroperitoneal schwannomas were positive for other keratins including K2, 4, 5, 8, 9, 10 and K14-20. Peripheral schwannomas showed GFAP-positivity in only three of 22 cases (14%), and all were negative for keratins, both cocktail and individual K. We conclude that crossreactivity of AE1/AE3 with other intermediate filament proteins, such as GFAP, as previously observed in brain and glioma tissue, probably accounts for the extensive keratin-positivity seen in some retroperitoneal schwannomas. However, focal expression of K1 and K7 cannot be ruled out. Keratin-positive schwannomas should not be confused with other keratin-positive tumors, such as sarcomatoid carcinoma, mesothelioma, and synovial sarcoma.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Female; Glial Fibrillary Acidic Protein; Humans; Immunohistochemistry; Keratins; Male; Middle Aged; Neurilemmoma; Peripheral Nervous System Neoplasms; Retroperitoneal Neoplasms

The authors present a case of pseudoglandular schwannoma with immunohistochemical findings consistent with epithelial metaplasia. Pseudoglandular schwannoma is a rare morphological variant of benign schwannoma characterized by the presence of glandlike structures lined with Schwann cells. To the best of the authors' knowledge, this is only the fifth case of pseudoglandular schwannoma reported in the literature. Clinical, imaging, and pathological findings are described. The pathological findings were consistent with a pseudoglandular schwannoma composed of typical Schwann cells arranged in an Antoni B pattern, with numerous large pseudocystic spaces. Serial immunohistochemical studies of tissue sections revealed that the cells lining the pseudoglandular spaces were not only diffusely reactive for S100 protein, but also demonstrated focal positivity for epithelial membrane antigen and cytokeratins AE and AE3. The particular immunohistochemical features of incompletely differentiated Schwann cells in the present case give support to the metaplastic theory of the origin of glandlike structures in benign peripheral nerve sheath tumors.

Topics: Adult; Cauda Equina; Epithelium; Humans; Immunohistochemistry; Keratins; Male; Metaplasia; Neurilemmoma; Peripheral Nervous System Neoplasms; S100 Proteins; Schwann Cells

Topics: Actins; Biopsy; Calmodulin-Binding Proteins; Cell Differentiation; Desmin; Humans; Immunohistochemistry; Keratins; Male; Middle Aged; Muscle, Smooth; Neurilemmoma; S100 Proteins

Transplantable tumor (KE) and clone cell (KE-F11) lines were established from a spontaneous malignant schwannoma found in an aged F344 rat. The primary tumor and KE tumors consisted of oval or spindle cells arranged in ill-defined bundles. Cultured KE-F11 cells exhibited polygonal or spindle configurations. Immunohistochemically, neoplastic cells in KE and KE-F11 reacted to vimentin, S-100 protein, neuron-specific enolase, myelin basic protein, and glial fibrillary acidic protein in varying degrees, indicating neurogenic features; occasional cells reacted to alpha-smooth muscle actin. Cells positive for lysosomal enzymes (acid phosphatase and non-specific esterase), and ED1 (rat macrophage specific) were observed in KE-F11, and electron microscopically, cells with many lysosomes were frequently present, indicating expression of macrophage-like phenotypes. Bioassay analysis revealed that KE-F11 cells produced high levels of nerve growth factor. DNA synthesis was inhibited by addition of transforming growth factor-beta1 (TGF-beta1), and Northern blot analysis revealed that expression of c-myc, a cell cycle-related immediate early gene, was depressed by TGF-beta1. Likely, TGF-beta1 is a factor capable of inhibiting cellular growth of Schwann cells. mRNA expression of the low-density lipoprotein receptor-related protein (LRP) was seen in KE-F11 cells by Northern blot analysis, and the level was decreased by lipopolysaccharide (LPS) treatment. LRP may be attributable to regulation of Schwann cell functions. KE-F11 cells seeded on laminin-coated dishes exhibited more extended cytoplasmic projections than on collagen type I-coated dishes. The present study provides evidence that biological properties of malignant schwannoma-derived cells might be affected by exogenous factors such as TGF-beta1, LPS and laminin. These tumor lines may be useful for studies on pathobiological characteristics of Schwann cells.

Topics: Actins; Animals; Blotting, Northern; Cell Count; Cell Line, Transformed; Desmin; Dose-Response Relationship, Drug; Genes, jun; Genes, myc; Glial Fibrillary Acidic Protein; In Vitro Techniques; Keratins; Lipopolysaccharides; Macrophages; Male; Microscopy, Electron; Myelin Basic Protein; Nerve Growth Factor; Neurilemmoma; PC12 Cells; Phenotype; Phosphopyruvate Hydratase; Rats; Rats, Inbred F344; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; S100 Proteins; Staining and Labeling; Time Factors; Transforming Growth Factor beta; Transforming Growth Factor beta1; Vimentin

Glandular schwannoma is a rare variant of schwannoma characterized by the presence of glands in an otherwise typical schwannoma. We report a patient with benign glandular schwannoma occurring on the scalp, a site not previously reported. Histologically, a well-defined, encapsulated oval nodule was observed in the subcutaneous tissue. The nodule was composed of a spindle cell component and glandular structures. The spindle cell component stained positively for S-100 protein. All of the glandular epithelium stained with CAM 5.2 and epithelial membrane antigen but not with S-100 protein. The glandular epithelium was focally positive for carcinoembryonic antigen. The histogenesis of the glandular elements in these tumours is still debated. The variable size of the glandular structures in our case was evidence against an entrapped normal sweat gland origin. The glandular epithelium did not stain with S-100 protein at all, but stained with CAM 5.2, which did not support a direct metaplastic origin of the epithelial elements from the schwannian component. A few scattered CAM 5.2-positive cells and microglandular structures in our case may be the initial differentiating epithelial elements possibly derived from pluripotential neural crest cells.

Topics: Adult; Biomarkers; Biomarkers, Tumor; Female; Head and Neck Neoplasms; Humans; Keratins; Neoplasm Proteins; Neurilemmoma; Scalp; Skin Neoplasms

Remnants of the branchial apparatus can produce lesions in the head and neck region in later life, often amenable to fine-needle aspiration (FNA) diagnosis. Yet such remnants or rudimentary lesions can remain clinically undetected and can later interfere with the cytologic interpretation of other deep lesions of the neck, as the present case demonstrates. In this case the lesion, which by a subsequent resection turned out to be a neurilemmoma, had been adequately sampled by the FNA, yet the cytologic diagnosis was sidetracked by the presence in the specimen of immature squamous epithelial tissue fragments and other elements (multinucleated histiocytes, calcifications), on the basis of which the diagnosis of an epithelial lesion, likely malignant, was made. The neck surgery and a preceding endoscopic examination of the mouth, pharynx, and larynx did not identify such a lesion, but a detailed microscopic examination of the fibroadipose tissue between the tumor and the peripharyngeal region revealed the presence of epithelial microfragments with morphology partly corresponding to that of the FNA cytology, highly indicative of a branchiogenic lesion in the peripharyngeal region. The basic embryology of the branchial apparatus resulting in such defects is presented, as well as tentative guidelines for recognizing material deriving from accidental sampling of such lesions during FNA investigations of deep-seated masses of the neck. Diagn. Cytopathol. 2000;22:157-160.

Topics: Aged; Biopsy, Needle; Branchial Region; Diagnostic Errors; Epithelial Cells; Head and Neck Neoplasms; Humans; Immunohistochemistry; Keratins; Male; Neurilemmoma

Although benign epithelioid peripheral nerve sheath tumors have been described, they are rare, and benign epithelioid schwannomas have not yet been established as a specific histologic variant. We present four cases of tumors which we believe would meet criteria to be classified as benign epithelioid schwannomas. Biopsy specimens obtained from four different patients were examined with routine and immunohistochemical staining. All the tumors were well-circumscribed lesions that were surrounded by a capsule containing EMA-positive cells. The cellular component was composed of epithelioid cells, in which there was a lack of mitotic activity. Immunohistochemical studies showed the tumor cells were S-100 protein and Leu 7 positive and HMB-45 negative. In addition, type IV collagen encircled individual cells within the tumor, indicating a continuous basal lamina. We report a group of cutaneous epithelioid schwannomas. Although the presence of such tumors is not unexpected, this diagnosis may not be initially considered because of this rare cytologic feature.

Topics: Adult; Antigens, Neoplasm; Collagen; Female; Humans; Immunohistochemistry; Keratins; Male; Melanoma-Specific Antigens; Mucin-1; Neoplasm Proteins; Nerve Sheath Neoplasms; Neurilemmoma; Peripheral Nervous System Neoplasms; S100 Proteins; Schwann Cells; Skin Neoplasms; Vimentin

A 27-year-old woman with a Malignant Triton Tumor (MTT), or malignant schwannoma with rhabdomyoblastic differentiation, located in the parotid cell and infiltrating the nasal sinuses and the left orbit is described. The initially resected tumor showed three recurrences within a 2 years follow-up period. During successive recurrences an increase in cellular density, number of mitoses and necrosis was noticed. Immunohistochemical analysis showed that the tumor was composed of a mixed population of cells. Some of them showed positivity for actin, desmin and myoglobin, while others were positive for S-100 protein, glial fibrillary acid protein, and IV-collagen. Cytokeratin stainings were negative. Up to now, 8 benign triton tumors and another 45 cases of MTT have been described. None of them was primarily located in the parotid gland, and infiltration to the orbital cavity has not been previously described.

Topics: Actins; Adult; Collagen; Desmin; Female; Glial Fibrillary Acidic Protein; Humans; Immunohistochemistry; Keratins; Myoglobin; Neoplasm Invasiveness; Neoplasm Recurrence, Local; Neurilemmoma; Orbital Neoplasms; Parotid Neoplasms; S100 Proteins

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

Merkel cells are an integral component of the cutaneous nervous system. They are commonly associated with dermal nerves under normal physiological conditions. We postulated that Merkel cells may be present in increased numbers within the epidermis overlying benign peripheral nerve sheath tumours such as neurilemomas and neurofibromas. Paraffin-embedded skin biopsy specimens from 21 patients with neurilemomas and 26 with neurofibromas, were analysed for the presence of Merkel cells using a standard immunohistochemical assay (avidin-biotin-peroxidase complex system) with an antibody to cytokeratin 8 (CAM 5.2). Ten cases of leiomyomas were examined as controls. Merkel cells were identified in the interfollicular area of the basal cell layer overlying 14 of 21 (67%) neurilemomas and nine of 26 (35%) neurofibromas. Merkel cells were more frequently observed in increased numbers in a linear array within the basal cell layer in neurilemomas than in neurofibromas, where they were found as individual cells. No Merkel cells were found in the epidermis overlying leiomyomas. The results of this study suggest that Merkel cells are quantitatively increased in the basal cell layer of the epidermis overlying benign peripheral nerve sheath tumours, particularly neurilemomas.

Topics: Humans; Keratins; Neurilemmoma; Neurofibroma; Skin; Skin Neoplasms

"Collagenous spherulosis" is the term used to describe striking concentric and radiating formations of collagen in tumors. It was originally used for these formations in epithelial tumors of the breast and subsequently in tumors of salivary glands. Recently, the histologic, immunohistochemical, and ultrastructural features were described in a chondroid syringoma. We report a case of collagenous spherulosis in a schwannoma. Routine histologic sections showed a circumscribed tumor in which the predominant feature was radiating fibrillar structures that tended to compress the cellular component of the tumor. Immunohistochemical studies showed that the cells were positive for glial fibrillary acidic protein (GFAP) and S-100 protein but negative for keratin. EMA showed a positive reaction in a thin band of cells around the periphery of the tumor consistent with perineurial cells. Type IV collagen stained around the periphery of the collagen formations. Electron microscopy revealed that the material was consistent with collagen. Our findings were essentially identical to those reported in the chondroid syringoma. This case confirms the findings of the previous study and shows that these unusual formations are not confined to tumors of epithelial origin. Because the architecture of the tumor is distorted, special stains may be required for correct diagnosis.

Topics: Adenoma, Pleomorphic; Adult; Antigens, CD; Antigens, Differentiation, T-Lymphocyte; CD57 Antigens; Cell Nucleus; Collagen; Female; Glial Fibrillary Acidic Protein; Humans; Immunohistochemistry; Keratins; Membrane Glycoproteins; Mucin-1; Mucins; Neoplasm Proteins; Neurilemmoma; Phosphopyruvate Hydratase; S100 Proteins; Skin Neoplasms; Staining and Labeling

A plexiform schwannoma (PFS) observed as a solitary mass in the dermis of a 6-month-old pig consisted of schwannoma cells of Antoni A type and B type. Neoplastic cells in Antoni A type areas sometimes showed cord-like outgrowths or a neurofibromatous pattern. Neoplastic cells in Antoni B type areas showed erythrophagocytosis, some encircling the microvasculature. Immunohistochemically, neoplastic cells were strongly positive for S-100 protein and vimentin. Peripheral parts of the nodules were cytokeratin (clone AE1/AE3)-positive, as in normal swine perineurial cells. Double immunostaining clearly demonstrated neoplastic cells doubly positive for both S-100 protein and cytokeratin, suggesting that S-100-positive Schwann cells and cytokeratin-positive perineurial cells are functional variants of the same cell type. Ultrastructurally, neoplastic cells in Antoni A type areas possessed characteristics of Schwann cells, such as cytoplasmic interdigitation, external laminae and intercellular junctions. At the periphery of the nodules, features of perineurial cells were detected. Neoplastic cells in Antoni B type areas seemed to be undergoing degenerative processes similar to those in Antoni A type regions and they contained many lysosomes. The neoplasm was generally similar in both location and histology to that seen in man, but there were some histological, immunohistochemical and ultrastructural differences. This is the first reported case of PFS in domestic animals.

Topics: Animals; Epidermis; Female; Immunohistochemistry; Keratins; Neurilemmoma; S100 Proteins; Skin Neoplasms; Swine; Swine Diseases; Vimentin

An immunohistochemical study using a comprehensive panel of antibodies to Schwann cell markers, intermediate filaments and extracellular matrix components has been performed on three cases of plexiform schwannoma. All tumour cells expressed S 100 protein, Leu 7-HNK 1 antigen and vimentin; glial fibrillary acidic protein was detected in many tumour cells. In addition, expression of cytokeratin was also demonstrated in one case. The associated extracellular matrix was found to be reactive with antibodies to laminin, heparan sulfate proteoglycan, fibronectin, type I, III, IV and VI collagen. It is concluded that Schwann cells producing their own extracellular matrix are the main components of these tumours. The significance of the cytokeratin expression and the possible role of the extracellular matrix in regulating Schwann cells' proliferation in peripheral nerve tumours are discussed.

Topics: Adult; Antigens, Differentiation; Biomarkers, Tumor; Cell Division; Child, Preschool; Collagen; Extracellular Matrix Proteins; Fibronectins; Glial Fibrillary Acidic Protein; Heparitin Sulfate; Humans; Immunohistochemistry; Intermediate Filament Proteins; Keratins; Laminin; Male; Neurilemmoma; S100 Proteins; Schwann Cells; Skin Neoplasms; Vimentin

We report a schwannoma with well differentiated ducts resembling cutaneous sweat ducts. The tumor presented as a painless mass near the left knee of a 41-year-old female. The mass had been present for many years. Some increase in size had been noticed over the previous 2 to 3 yr. The bulk of the tumor was composed of spindle cells with the appearance of Antoni A and Antoni B tissue. Rare mitotic figures were noted. In several areas of the tumor, numerous well-differentiated ducts were present. Most resembled normal cutaneous sweat ducts. In some areas, cystic dilatation of the ducts was present. Focal areas demonstrated poorly formed ducts and single cells with prominent nuclei and ample cytoplasm. Well formed ducts, poorly formed ducts, and single cells marked with AE 1/3 (keratin) and epithelial membrane antigen. The spindle cell proliferation marked for S 100 protein and vimentin. Sweat duct differentiation has not been reported previously in either benign or malignant schwannoma. Light and electron microscopic features of this tumor are presented.

Topics: Adult; Cell Transformation, Neoplastic; Female; Humans; Immunohistochemistry; Keratins; Microscopy, Electron; Neurilemmoma; S100 Proteins; Skin Neoplasms; Sweat Glands; 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

Sixty-three pure mesenchymal tumors of the uterus were studied to explore the value of immunostaining in the diagnosis of unusual mesenchymal tumors encountered in the uterus, some not reported previously. Each tumor was evaluated using a panel of immunostains including actin, desmin, vimentin, S-100 protein, and cytokeratin. The final classification, which incorporated the immunohistochemical findings, resulted in the identification of 33 relatively common pure mesenchymal tumors (13 benign and malignant endometrial stromal tumors and 20 benign and malignant smooth muscle tumors) and 30 uncommon tumors (five leiomyosarcomas with osteoclastic giant cells, two xanthomatous leiomyosarcomas, one melanotic schwannoma, one pure rhabdomyosarcoma, one neurofibroma, five plexiform tumorlets, and 15 combined smooth muscle-stromal tumors). The normal endometrial stroma, present in 14 cases, invariably showed a negative reaction for all antibodies. With rare exceptions, the pure endometrial stromal tumors displayed a negative immunoreaction for all antibodies utilized, while the pure smooth muscle tumors consistently showed a positive reaction for actin. Only the two tumors of neural origin (a neurofibroma and a melanotic schwannoma) reacted with S-100 protein. Immunostaining influenced most the final classification of neoplasms initially interpreted as uterine tumors with a sex-cord stromal pattern, endometrial stromal tumors that diverged from the classic lesions by having a spindle cell component, and intravascular leiomyomas with areas of compact proliferation of small round cells with prominent vascularity. All tumors in these three groups were reclassified as combined smooth muscle-stromal tumors following immunohistochemical studies.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Actins; Aged; Aged, 80 and over; Child, Preschool; Desmin; Female; Humans; Immunohistochemistry; Keratins; Leiomyosarcoma; Mesenchymoma; Middle Aged; Neurilemmoma; Neurofibroma; Rhabdomyosarcoma; S100 Proteins; Uterine Neoplasms; Vimentin

Seventy-seven cases of meningioma (15 with single or multiple recurrences), selected on the basis of their histologic subtypes, and nine cases of neurilemoma were analyzed immunohistochemically for the presence of the five classes of intermediate filament proteins, neuron-specific enolase (NSE), protein S-100, epithelial membrane antigen (EMA), and HNK-1 (Leu-7). Most antibodies were studied with the alkaline phosphatase-antialkaline phosphatase method. The peroxidase-anti-peroxidase and avidin-biotin-complex methods were used for Leu-7 and NSE, respectively. Meningiomas were subdivided into groups showing cytokeratin or protein S-100 positivity. Coexpression of these two markers was rare (5%) and occurred in meningotheliomatous meningiomas only. Only in these cases was cytokeratin expression more frequent than in meningiomas taken together (33% versus 20%). In contrast, protein S-100 expression was less frequent (46% versus 60% on average). In fibrous meningiomas, both cytokeratins and NSE were expressed less frequently than on average (11% versus 20%, 67% versus 88%, respectively). Protein S-100 occurred in a higher percentage of cases. Transitional meningiomas did not show cytokeratin expression. Protein S-100 occurred in a higher percentage of cases. Transitional meningiomas did not show cytokeratin expression. Protein S-100 was expressed slightly more often than in the other subtypes. Psam-momatous meningiomas coexpressed more markers than any other subtype. Hemangioblastic and hemangiopericytic forms did not stain for EMA, but otherwise showed a staining profile similar to that of meningiomas. HNK-1 was expressed in 29% of meningiomas, particularly among tumors with anaplastic histologic features. There was no marker that retrospectively indicated impending recurrences.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Antigens, Differentiation; CD57 Antigens; Child; Child, Preschool; Female; Glial Fibrillary Acidic Protein; Humans; Intermediate Filament Proteins; Keratins; Male; Membrane Glycoproteins; Meningioma; Middle Aged; Mucin-1; Nervous System Neoplasms; Neurilemmoma; Neurofilament Proteins; Phosphopyruvate Hydratase; S100 Proteins; Vimentin

A malignant Triton tumor in a 9-year-old boy is described. The first biopsy which was taken from the thenar prominence was diagnosed as a monophasic fibrous synovial sarcoma based on the finding of a spindle cell neoplasm with plump nuclei and cytokeratin expression. The true nature of the tumor became apparent when a second biopsy was investigated. In this specimen a rhabdomyosarcomatous component was found in association with a spindle cell sarcoma fulfilling the criteria of a malignant schwannoma. Immunohistochemical staining using antibodies against vimentin, desmin, muscle-specific actin, cytokeratin, glial fibrillary acidic protein, protein S-100, Leu 7 and myoglobin served to distinguish the two tumor components and documented the possible reactivity of malignant Triton tumor for cytokeratins.

Topics: Biopsy; Child; Hand; Humans; Immunoenzyme Techniques; Keratins; Male; Neurilemmoma

The Cavitron ultrasonic surgical aspirator (CUSA) is a dissecting system that allows quick and effective removal of CNS tumors without traction or excessive manipulation of normal tissue. In this article, the immunoperoxidase staining patterns of cytology specimens obtained with the CUSA are compared with those from their corresponding resected surgical specimens employing a battery of monoclonal and polyclonal antibodies. Eleven cases of meningioma, three cases of glioblastoma multiforme, one astrocytoma, and two schwannomas were evaluated. In both CUSA cytologic biopsies and surgical biopsies, all the meningiomas showed strong staining for vimentin and epithelial membrane antigen, while two showed focal staining for cytokeratins. The glioblastoma multiforme and astrocytoma cases showed positivity for vimentin, S-100 protein, and glial fibrillary acidic protein, while the schwannomas stained positively for vimentin and S-100 protein. With only rare exceptions, the immunocytochemistry of the CUSA and surgical specimens correlated well in all of these cases in terms of strength of reaction and localization. There were no false-positive staining reactions in the CUSA material. This study suggests that reliable morphologic and immunoperoxidase studies can be performed on cytologic material obtained by the CUSA, which could aid in making an accurate and specific diagnosis of a variety of CNS tumors.

Topics: Astrocytoma; Biopsy; Cytodiagnosis; Glial Fibrillary Acidic Protein; Glioblastoma; Humans; Immunoenzyme Techniques; Keratins; Meningioma; Neoplasms, Nerve Tissue; Neurilemmoma; Neurosurgery; S100 Proteins; Suction; Ultrasonic Therapy; Vimentin

Specimens of neoplastic tissues from 19 dogs and 4 cats were examined immunohistochemically for intermediate filament expression, using commercially available antibodies. Staining was observed in a wide range of tumor tissues and in normal internal controls by use of antibodies to vimentin, desmin, glial fibrillary acidic protein, and low and high molecular weight cytokeratins. Intermediate filament expression was found to be consistent with light and/or electron microscopic findings, and hence believed to be an accurate indicator of tumor histogenesis in cats and dogs. Three fixatives were evaluated for their relative abilities to preserve antigenicity. Absolute alcohol was superior to B5 fixative and both were superior to formalin. Some tissues that clearly displayed intermediate filament antigens with alcohol and B5 fixative failed to stain when fixed in formalin.

Topics: Adenocarcinoma; Animals; Astrocytoma; Cat Diseases; Cats; Cytoskeleton; Desmin; Dog Diseases; Dogs; Immunohistochemistry; Intermediate Filament Proteins; Intermediate Filaments; Keratins; Leiomyosarcoma; Melanoma; Neoplasms; Neurilemmoma

Formalin-fixed, paraffin-embedded sections of 59 ultrastructurally confirmed nerve sheath tumors (NSTs) that included 27 benign schwannomas, five neurofibromas, and 27 malignant schwannomas were studied by the avidin-biotin-peroxidase complex method using antibodies directed against glial fibrillary acidic protein (GFAP), keratin, S-100 protein, vimentin, and desmin. GFAP was expressed by 33% of the benign schwannomas, 40% of the neurofibromas, and 7% of the malignant schwannomas. Keratin was expressed by 7% of the benign schwannomas and 4% of the malignant schwannomas. S-100 protein was expressed by 100% of the benign NSTs and by 40% of the malignant schwannomas. Vimentin was observed in 100% of the benign NSTs and in 85% of the malignant schwannomas. None of the cases stained for desmin. GFAP and cytokeratin expression could not be predicted on the basis of tumor light microscopy or ultrastructure. These findings are of practical importance in routine surgical pathology, particularly with respect to the differential diagnosis of gliomas located in the central nervous system and in immunohistochemical studies of peripherally located, poorly differentiated neoplasms.

Topics: Desmin; Glial Fibrillary Acidic Protein; Humans; Immunohistochemistry; Keratins; Microscopy, Electron; Neurilemmoma; Neurofibroma; S100 Proteins; Vimentin

1,25-Dihydroxyvitamin D3 (1,25(OH)2D3) dependent growth and differentiation of 6 tumor cell lines has been determined by the use of the monolayer proliferation assay. Cell lines of 4 gastro-intestinal carcinomas, 1 malignant schwannoma, and 1 malignant histiocytoma have been established and characterized. Cells were incubated for 4, 7, and 11 days in the presence of 0.8 or 8 nM 1,25(OH)2D3 and for control without addition of the hormone. Proliferation rates of 1,25(OH)2D3 treated cells were compared with cell growth in the untreated controls. Five out of 6 cell lines showed a 1,25(OH)2D3 dependent growth pattern. With 8 nM 1,25(OH)2D3 they were all inhibited. With 0.8 nM, 3 of them were inhibited at any time of the test period, whereas 1 was stimulated at day 4 and inhibited at days 7 and 11. One cell line was stimulated at days 4, 7, and 11 when incubated with 0.8 nM 1,25(OH)2D3. No striking morphological changes could be observed in the presence of 1,25(OH)2D3. We conclude that 1,25(OH)2D3 dependent cells in vitro are not necessarily growth-inhibited by this compound. Thus, 1,25(OH)2D3 is not an exclusively proliferation inhibiting agent.

Topics: Antigens, Neoplasm; Calcitriol; Cell Division; Gastrointestinal Neoplasms; Histiocytoma, Benign Fibrous; Humans; Immunoenzyme Techniques; Keratins; Neoplasms; Neurilemmoma; Tumor Cells, Cultured; Vimentin

Meningiomas are composed of cells which display both mesenchymal and epithelial features. To investigate the epithelial nature of these cells, we studied the distribution of epithelial membrane antigen (EMA) in 22 meningiomas; for comparison, we also studied eight central schwannomas, neoplasms with which meningiomas sometimes may be confused histologically. All 22 meningiomas (12 transitional, six meningotheliomatous, three fibroblastic, and one psammomatous) demonstrated immunoreactive EMA, whereas all eight schwannomas were EMA-negative. There was no consistent relationship between histologic growth pattern and nature of EMA staining in the meningiomas: meningothelial areas, spindle cell areas, and whorls all showed EMA immunoreactivity of varying degrees. We also evaluated the distribution of S-100 protein and keratin in these tumors. All schwannomas showed diffuse S-100 positivity, which was often more intense in the nuclei than in the cytoplasm. In nine meningiomas (41%), S-100 immunostaining was observed, but this was usually focal, and nuclear staining was never more intense than cytoplasmic staining. One meningioma, but none of the schwannomas, showed clusters of keratin-positive cells. We conclude the following: EMA immunoreactivity is a characteristic feature of meningiomas, regardless of pattern of growth, and the combination of immunoperoxidase staining for EMA and S-100 protein may be used to distinguish meningiomas from schwannomas in problematic cases.

Topics: Antigens; Diagnosis, Differential; Female; Humans; Immunoenzyme Techniques; Keratins; Male; Membrane Proteins; Meningeal Neoplasms; Meninges; Meningioma; Mucin-1; Neurilemmoma; S100 Proteins