bromochloroacetic-acid and Sarcoma--Ewing

Hyalinising clear cell carcinoma (HCCC) of the lung is a rare tumor, with only 12 reported cases. To improve the differential diagnosis, the aim of this study was to clarify the clinicopathological characteristics, immunophenotype, and molecular characteristics of HCCC of the lung and relate these to prognosis.. Sections of HCCC of the lung were collected from a patient for pathological observation, immunohistochemistry, histochemistry, and fluorescence in situ hybridization; the clinical, pathological, and molecular characteristics were compared with those reported in the literature.. The tumor had a well-demarcated border nodule with a maximal diameter of 2.5 cm. Microscopic findings showed either clear or eosinophilic cytoplasm in the tumor cells. Growth was predominantly in the sheets, nests, and trabeculae in a background of hyalinised, fibrotic stroma, and mucus degeneration. Immunohistochemistry showed that the tumor cells expressed cytokeratin 7, P63, P40, CK5/6, Pan Cytokeratin (PCK), and epithelial membrane antigen, whereas they were negative for thyroid transcription factor-1, napsin A, CD10, vimentin, and smooth muscle actin. The Ki67 proliferation index was 5%. The tumor was positive for both period acid-Schiff (PAS) and Alcian blue-PAS, with a small amount of mucus staining positive for PAS-diastase. Fluorescence in situ hybridization revealed Ewing sarcoma breakpoint region 1 rearrangement and Ewing sarcoma breakpoint region 1-activating transcription factor 1 fusion.. HCCC is a low-grade carcinoma with excellent prognosis. Tumour necrosis may be a potential risk factor for recurrence and metastasis. Our review of reported cases suggests that regional lymph node dissection combined with lobectomy is a safer treatment than only lobectomy for HCCC of the lung.

Topics: Adenocarcinoma, Clear Cell; Biomarkers, Tumor; Humans; In Situ Hybridization, Fluorescence; Keratins; Lung; Sarcoma, Ewing

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

Ewing sarcoma (ES) is a highly malignant tumor that rarely occurs in the uterine cervix. Herein, we report 8 cases with ES arising primarily in the uterine cervix by focusing on clinicopathologic and molecular cytogenetic features and differential diagnoses. Eight cases of cervical ES were diagnosed between February, 2012, and September, 2018. The age of patients ranged from 13 to 47 years. Abnormal vaginal bleeding and lower abdominal pain were the most common symptoms. Histologically, the tumor was composed of uniform, round, and oval cells with a narrow rim of eosinophilic cytoplasm. Fibrous septa were observed between tumor cell nests. The tumors showed brisk mitotic activity and areas of coagulative necrosis. According to immunohistochemical studies, 50% (4/8) of the cases were positive for cytokeratin (AE1/AE3), and 87.5% (7/8) were positive for synaptophysin, which resulted in a diagnostic confusion with small cell carcinoma, primarily when dealing with small cervical biopsies. Molecular testing demonstrated the rearrangement of the EWSR1 gene in all of the 8 cases, which confirmed the diagnosis of ES. Although rare, ES should be considered as indicators of cervical small round cell neoplasms. Molecular analysis may greatly contribute to the final diagnosis of ES occurring in this unusual location.

Topics: Adolescent; Adult; Biomarkers, Tumor; Diagnosis, Differential; Female; Gene Rearrangement; Humans; Immunohistochemistry; In Situ Hybridization, Fluorescence; Keratins; Middle Aged; Predictive Value of Tests; RNA-Binding Protein EWS; Sarcoma, Ewing; Uterine Neoplasms; Young Adult

Ewing's sarcoma (ES) is a malignancy primarily affecting bone tissue that is commonly diagnosed in adolescents and young adults. Its occurrence in the head and neck region is unusual and generally involves the mandible and maxilla. An extensive review of the literature shows only few cases of the oral ES in patients under the age of 5. This paper reports a rare case of ES of the mandible in a 4-year-old girl, which had been previously misdiagnosed and treated as a dental abscess. In the clinical examination, a hard immobile expansive mass of 5 cm in diameter was observed on the left side of the mandible. Radiographic examination revealed a radiolucent lesion with ill-defined borders and wide vestibular bone plate destruction. Microscopically, the tumor was composed by monotonous small round cells that exhibited immunoreactivity for CD99, vimentin and pancytokeratin. The patient was subjected to multiagent chemotherapy with ifosfamide, carboplatin, etoposide, vincristine, cyclophosfamide and doxorrubycin (VAC/ICE regimen). However, after the first chemotherapeutic cycle, the patient died due to disseminated infection. This case elucidates the importance of professional knowledge of the relevant aspects of malignant lesions such as ES.

Topics: 12E7 Antigen; Abscess; Antigens, CD; Antineoplastic Combined Chemotherapy Protocols; Cell Adhesion Molecules; Child, Preschool; Diagnostic Errors; Fatal Outcome; Female; Humans; Keratins; Mandibular Neoplasms; Sarcoma, Ewing; Tomography, X-Ray Computed; Tooth Diseases; Vimentin

Ewing's sarcoma, a highly malignant neoplasm, is characterized by an 11;22 translocation [t(11;22) (q24;q12)], resulting in the fusion of genes FLII and EWS. Adamantinoma of extragnathic bones, a low-grade malignant neoplasm with epithelial features, is not typically considered in the differential diagnosis of Ewing's sarcoma. In this study, three osseous Ewing's sarcomas with histological, immunohistochemical, or ultrastructural epithelial features were subjected to reverse transcription-polymerase chain reaction and sequencing studies for the Ewing's sarcoma molecular rearrangement. (Two of the three cases were originally described as adamantinomas or nontypical Ewing's sarcoma before the availability of genetic characterization.) In addition, traditional cytogenetic analysis and a unique combined interphase molecular cytogenetic/ immunocytochemical approach with bicolor 11;22 translocation breakpoint flanking probes (cosmids) and pancytokeratin antibodies were performed on one neoplasm. At(11;22) (q24;q12) was found in one neoplasm and a type II EWS/FLI-1 fusion transcript was detected in all three neoplasms. The combined genetic/immunocytochemical approach revealed the presence of the 11 ;22 translocation in the nuclei of cytokeratin immunoreactive cells. These genotypic and phenotypic findings delineate a novel Ewing's sarcoma histologic variant, "adamantinoma-like Ewing's sarcoma."

Topics: Adolescent; Bone Neoplasms; Cytogenetics; Desmosomes; Diagnosis, Differential; Humans; In Situ Hybridization, Fluorescence; Intermediate Filaments; Keratins; Male; Neoplasms, Glandular and Epithelial; Oncogene Proteins, Fusion; Proto-Oncogene Protein c-fli-1; Radiography; Reverse Transcriptase Polymerase Chain Reaction; RNA-Binding Protein EWS; RNA, Neoplasm; Sarcoma, Ewing; Transcription Factors

Topics: Adamantinoma; Adolescent; Adult; Ameloblastoma; Biomarkers, Tumor; Child; Female; Head and Neck Neoplasms; Humans; Immunohistochemistry; Keratins; Male; RNA-Binding Protein EWS; Sarcoma, Ewing; Young Adult

Extraskeletal Ewing sarcoma presenting as intra-abdominal or pelvic disease in adult female patients is very rare and may lead to diagnostic difficulty due to clinical and histologic overlap with Mullerian adenocarcinomas, which are far more common. We report a case of an intra-abdominal Ewing sarcoma in a postmenopausal female patient whose clinical and radiological presentation closely resembled that of peritoneal carcinomatosis. Biopsy of an omental nodule revealed numerous histologic features suggestive of a Mullerian carcinoma, including gland-like rosettes, strong, diffuse PAX8 immunoreactivity and cytokeratin expression. After excluding other differential diagnostic considerations, the possibility that this might represent an intra-abdominal Ewing sarcoma was entertained. Reverse transcriptase polymerase chain reaction testing demonstrated the presence of an EWSR1-ERG fusion transcript, confirming the diagnosis. The differential diagnostic considerations when dealing with this unusual clinical scenario and the uncommon yet important pitfall of PAX8 immunoreactivity in Ewing sarcoma are discussed.

Topics: Abdomen; Adenosarcoma; Carcinoma; Diagnosis, Differential; Female; Gene Fusion; Humans; Keratins; Middle Aged; Mullerian Ducts; PAX8 Transcription Factor; Peritoneal Neoplasms; Postmenopause; RNA-Binding Protein EWS; Sarcoma, Ewing; Transcriptional Regulator ERG

Adamantinoma-like Ewing Sarcoma (ALES) is a rare subtype of Ewing sarcoma family of tumors (EFTs) which are defined by their EWSR1 gene rearrangements. We present a case of a 15-year old female with a swelling in her anterior neck of 4 months duration which had recently begun to rapidly grow in size. Fine needle aspiration showed a small blue round cell tumor with immunoreactivity for cytokeratin, CD99 and FLI1. Material for molecular testing was available on the resection specimen. Demonstration of t(11;22) (EWS-FLI1) was helpful in establishing the diagnosis.

Topics: 12E7 Antigen; Adamantinoma; Adolescent; Biomarkers, Tumor; Biopsy, Fine-Needle; Diagnosis, Differential; Female; Head and Neck Neoplasms; Humans; In Situ Hybridization, Fluorescence; Keratins; Oncogene Proteins, Fusion; Proto-Oncogene Protein c-fli-1; RNA-Binding Protein EWS; Sarcoma, Ewing; Thyroid Gland; Thyroidectomy

Topics: Adult; Biomarkers, Tumor; Calmodulin-Binding Proteins; Diagnosis, Differential; Gastrointestinal Neoplasms; Gastrointestinal Stromal Tumors; High-Throughput Nucleotide Sequencing; Humans; Immunohistochemistry; In Situ Hybridization, Fluorescence; Keratins; Male; MART-1 Antigen; Melanoma; Middle Aged; Neoplasm Recurrence, Local; Neuroectodermal Tumors; RNA-Binding Proteins; S100 Proteins; Sarcoma, Ewing; SOXE Transcription Factors; Synaptophysin

Ewing sarcoma family tumors (EFTs) of the head and neck are rare and may be difficult to diagnose, as they display significant histologic overlap with other more common undifferentiated small blue round cell malignancies. Occasionally, EFTs may exhibit overt epithelial differentiation in the form of diffuse cytokeratin immunoexpression or squamous pearls, resembling the so-called adamantinoma-like EFTs and being challenging to distinguish from bona fide carcinomas. Furthermore, the presence of EWSR1 gene rearrangement correlated with strong keratin expression may suggest a myoepithelial carcinoma. Herein, we analyze a series of 7 adamantinoma-like EFTs of the head and neck, most of them being initially misdiagnosed as carcinomas because of their anatomic location and strong cytokeratin immunoexpression, and subsequently reclassified as EFT by molecular techniques. The tumors arose in the sinonasal tract (n=2), parotid gland (n=2), thyroid gland (n=2), and orbit (n=1), in patients ranging in age from 7 to 56 years (mean, 31 y). Microscopically, they departed from the typical EFT morphology by growing as nests with peripheral nuclear palisading and prominent interlobular fibrosis, imparting a distinctly basaloid appearance. Moreover, 2 cases exhibited overt keratinization in the form of squamous pearls, and 1 sinonasal tumor demonstrated areas of intraepithelial growth. All cases were positive for CD99, pancytokeratin, and p40. A subset of cases showed synaptophysin, S100 protein, and/or p16 reactivity, further confounding the diagnosis. Fluorescence in situ hybridization assays showed EWSR1 and FLI1 rearrangements in all cases. Our results reinforce that a subset of head and neck EFTs may show strong cytokeratin expression or focal keratinization, and are therefore histologically indistinguishable from more common true epithelial neoplasms. Thus, CD99 should be included in the immunopanel of a round cell malignancy regardless of strong cytokeratin expression or anatomic location, and a strong and diffuse CD99 positivity should prompt molecular testing for the presence of EWSR1 gene rearrangements.

Topics: 12E7 Antigen; Adamantinoma; Adolescent; Adult; Antigens, CD; Biomarkers, Tumor; Biopsy; Bone Neoplasms; Calmodulin-Binding Proteins; Cell Adhesion Molecules; Cell Differentiation; Child; Diagnosis, Differential; Female; Gene Rearrangement; Head and Neck Neoplasms; Humans; Immunohistochemistry; In Situ Hybridization, Fluorescence; Keratins; Male; Middle Aged; Myoepithelioma; Neuroectodermal Tumors, Primitive, Peripheral; Predictive Value of Tests; Proto-Oncogene Protein c-fli-1; RNA-Binding Protein EWS; RNA-Binding Proteins; Sarcoma, Ewing; Tissue Array Analysis; Young Adult

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

Topics: Adamantinoma; Adult; Diagnosis, Differential; Female; Femur; Follow-Up Studies; Humans; Humerus; Ilium; Keratins; Male; Middle Aged; Mucin-1; Retrospective Studies; Sarcoma, Ewing; Sarcoma, Synovial; Tibia; Tomography, X-Ray Computed; Young Adult

Ewing sarcoma (ES)/ primitive neuroectodermal tumour (PNET) is an aggressive malignant neoplasm affecting mainly children and young adults. The tumour is included with other primitive neoplasms under the category of small round cell tumour. Cytokeratin expression in ES/PNET has been described in sporadic case reports as well as a few systemic series. We studied this feature in Malaysian patients diagnosed in University Malaya Medical Centre on the basis of typical morphology and immunohistochemical assays. Immunohistochemical staining for AE1/AE3 and MNF116 were performed in 43 cases. Cytokeratin was expressed in 17 cases (39.5%) in focal, intermediate or diffuse patterns. There was no significant association between cytokeratin immunoreactivity and the following parameters: patient age, sex, skeletal and extraskeletal primary location as well as primary, metastastic or recurrent tumours or chemotherapy treatment. A significant association between cytokeratin and neuron specific enolase (NSE) expression was demonstrated. Our study supports evidence of epithelial differentiation in ES/PNET and emphasizes that the expression of cytokeratin does not exclude ES/PNET in the differential diagnosis of small round cell tumours.

Topics: Adolescent; Adult; Aged; Biomarkers, Tumor; Child; Child, Preschool; Female; Humans; Immunohistochemistry; Keratins; Malaysia; Male; Middle Aged; Neuroectodermal Tumors, Primitive; Sarcoma, Ewing; Young Adult

To study the clinicopathologic features and histologic differential diagnosis of small cell neuroendocrine carcinoma (SmCC) of kidney.. The clinicopathologic features of 12 cases of SmCC of kidney encountered during the period from 1999 to 2010 were retrospectively reviewed.. Six cases of primary and 6 cases of metastatic SmCC involving kidney were identified. Amongst the primary renal SmCC, 2 were located in renal parenchyma and 4 in renal pelvis. Chest X-ray showed negative findings. Five of them underwent radical nephrectomy. On gross examination, the tumor was located centrally around the renal pelvis in 4 cases and peripherally in renal parenchyma in 1 case. On the other hand, 4 of the 6 cases of metastatic SmCC were discovered during therapy for pulmonary SmCC. Two of these patients presented with abdominal pain and gross hematuria, with lung and renal tumor masses identified simultaneously. The diagnosis of all the 6 cases of metastatic SmCC was confirmed by fine needle aspiration biopsy. Microscopically, pure SmCC was demonstrated in the 2 cases of primary renal parenchymal SmCC and 6 cases of metastatic SmCC. The 4 primary renal pelvic SmCC coexisted with urothelial carcinoma component. On immunohistochemical study, all cases were positive for cytokeratin, synaptophysin and CD56. All metastatic cases and 4 primary cases were also positive for TTF-1. Of six patients with primary SmCC two died 4 and 9 months after operation, and two were alive with a follow-up of 25 and 138 months, respectively. Five of six cases with metastatic SmCC died 3 - 8 months after diagnosis. The other 3 cases were failed to follow-up.. Both primary and metastatic SmCC can be found in the kidney. Although rare, primary SmCC is located either in renal parenchyma or in pelvis. The diagnosis of SmCC relies on morphologic examination and immunohistochemical study. TTF-1 immunostaining cannot reliably distinguish primary from metastatic SmCC in kidney. Correlation with clinicoradiologic findings and demonstration of coexisting urothelial carcinoma component (if any) is helpful in delineation of the tumor origin.

Topics: Adult; Aged; Carcinoma, Neuroendocrine; Carcinoma, Renal Cell; Carcinoma, Small Cell; CD56 Antigen; Diagnosis, Differential; Female; Follow-Up Studies; Humans; Keratins; Kidney Neoplasms; Lung Neoplasms; Lymphoma; Male; Middle Aged; Nephrectomy; Nuclear Proteins; Retrospective Studies; Sarcoma, Ewing; Synaptophysin; Thyroid Nuclear Factor 1; Transcription Factors; Treatment Outcome; Wilms Tumor

Epithelial marker expression has been reported in Ewing's sarcoma family of tumors (ESFT). However, cytokeratin (CK), epithelial membrane antigen (EMA), and carcino embryonic antigen (CEA) prevalence has not been assessed thoroughly in a large series of genetically confirmed ESFT. The aim of the present study is to confirm the presence of epithelial markers in a large group of ESFT tested genetically for any of their specific gene fusions and the differential diagnosis with other small round cell tumors. To establish the prevalence of epithelial markers, we then performed immunohistochemical studies with antibodies CK (AE1/AE3), CK8/18, CK34β12, EMA, E-cadherin, and CEA on 415 genetically confirmed ESFT. Immunoreactivity to cytokeratin, EMA, and CEA was present in 19.2%, 6.6%, and 20.8% of cases, respectively. There was no significant association between epithelial markers and histological subtypes, but the atypical variant of ESFT expressed these markers in a high proportion compared with the peripheral neuroectodermal tumors and the conventional variant. The present findings confirm that epithelial marker expression in ESFT, including EMA and CEA, does not rule out a diagnosis of ESFT, and the integration of clinical, radiological, histopathological, immunohistochemical, and molecular genetic findings should form the basis for the diagnosis of bone and soft tissue sarcomas, especially in tumors with atypical or unusual phenotype.

Topics: Biomarkers, Tumor; Bone Neoplasms; Carcinoembryonic Antigen; Humans; Immunohistochemistry; Keratins; Mucin-1; Sarcoma, Ewing; Tissue Array Analysis

A great deal of attention has been given to epithelial differentiation in Ewing family of tumors (EFTs) in recent years, with studies showing variable keratin expression in 20% to 32% of cases. A 29-year-old man presented with a right-sided Horner syndrome suggesting a sympathetic chain related lesion. No radiologic evidence of a mass was appreciated initially. Several months later, he developed right vocal cord palsy and a large right-sided neck mass. An open biopsy demonstrated a high-grade malignant neoplasm with sheets of undifferentiated round cells infiltrating soft tissues and a large peripheral branch of the vagus nerve. Focally, the tumor abruptly produced keratinizing cells and frank squamous pearls. The tumor showed diffuse expression of CD99, high molecular weight keratin, p63, cytokeratin (CK) 5/6, AE1/AE3, CAM5.2, CK19, and focal CK14. It was negative for muscle-specific actin, desmin, MyoD1, MYF-4, S100, and CK7. Ultrastructurally, abundant cytoplasmic tonofilaments and well-formed desmosomes were demonstrated. Initial diagnosis was a metastatic squamous cell carcinoma of probable upper aerodigestive origin. Subsequently, the tumor was shown to harbor the t(11;22) involving EWSR1 and FLI-1 by reverse transcription-polymerase chain reaction, characteristic of EFT's, which was confirmed by dual color break apart fluorescence in-situ hybridization analysis. This tumor is related to, if not an example of the recently described "adamantinoma-like" EFT and demonstrates a potential diagnostic pitfall. It seems to be the first EFT to arise within, or in close proximity to the cervical sympathetic chain of ganglia. It is also the first EFT with complex epithelial differentiation arising outside the extremities and with diffuse expression of high molecular weight keratin and p63.

Topics: Adult; Biomarkers, Tumor; Epithelium; Head and Neck Neoplasms; Horner Syndrome; Humans; Immunohistochemistry; In Situ Hybridization, Fluorescence; Keratins; Male; Membrane Proteins; Oncogene Proteins, Fusion; Proto-Oncogene Protein c-fli-1; Reverse Transcriptase Polymerase Chain Reaction; RNA-Binding Protein EWS; Sarcoma, Ewing; Translocation, Genetic; Vagus Nerve

As a result of overlapping morphologic and immunohistochemical features, it can be difficult to distinguish synovial sarcoma, malignant peripheral nerve sheath tumor, and Ewing sarcoma/primitive neuroectodermal tumor in core biopsies. To analyze and compare immunohistochemical profiles, we stained tissue microarrays of 23 synovial sarcomas, 23 malignant peripheral nerve sheath tumors, and 27 Ewing sarcomas with 22 antibodies potentially useful in the differential diagnosis, and analyzed the data with cluster analysis. Stain intensity was scored as none, weak, or strong. For CD99, tumors with membranous accentuation were independently categorized. Cluster analysis sorted five groups, with like tumors clustering together. Synovial sarcoma clustered into two groups: one cytokeratin and EMA positive (n = 11), the other mostly cytokeratin negative, EMA positive, bcl-2 positive and mostly CD56 positive (n = 9). Malignant peripheral nerve sheath tumor clustered into two groups: one S100 positive, with nestin and NGFR positivity in most (n = 10), the other mostly S100 negative, and variably but mostly weakly positive for nestin and NGFR (n = 11). Ewing sarcomas clustered into a single group driven by membranous CD99 staining. Thirteen cases failed to cluster (outliers), while three Ewing sarcomas clustered into groups of other tumor types. Paired antibodies for each tumor type determined by visual assessment of cluster analysis data and statistical calculations of specificity, sensitivity, and predictive values showed that EMA/CK7 for synovial sarcoma, nestin/S100 for malignant peripheral nerve sheath tumor, and membranous CD99/Fli-1 for Ewing sarcoma yielded high specificity and positive predictive values. Cluster analysis also highlighted aberrant staining reactions and diagnostic pitfalls in these tumors. Hierarchical cluster analysis is an effective method for analyzing high-volume immunohistochemical data.

Topics: 12E7 Antigen; Antigens, CD; Biomarkers, Tumor; Bone Neoplasms; CD56 Antigen; Cell Adhesion Molecules; Cluster Analysis; Diagnosis, Differential; Humans; Immunohistochemistry; Keratins; Mucin-1; Nectins; Nerve Sheath Neoplasms; Nerve Tissue Proteins; Proto-Oncogene Protein c-fli-1; Receptors, Nerve Growth Factor; S100 Proteins; Sarcoma, Ewing; Sarcoma, Synovial

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

Peripheral primitive neuroectodermal tumor (PNET)/Ewing's sarcoma (ES) of the central nervous system is extremely rare and should be differentiated from central PNET and other small blue round cell tumors. We describe a case of a meningeal peripheral PNET/ES of the spinal cord in an 11-year-old boy. Immunohistochemically, the small blue round cell tumor showed expression of epithelial markers and of CD99, thus posing an important differential diagnostic problem with a poorly differentiated synovial sarcoma. Fluorescence in situ hybridization revealed rearrangement of the EWS gene, as seen in peripheral PNET/ES. Peripheral PNET/ES does occur in the central nervous system, but its diagnosis can be extremely difficult on morphologic and immunohistochemical grounds alone. Genetic analysis plays a key role in its distinction from other small blue round cell tumors.

Topics: Antineoplastic Combined Chemotherapy Protocols; Biomarkers, Tumor; Bone Neoplasms; Child; Diagnosis, Differential; Humans; Keratins; Laminectomy; Male; Meninges; Mucin-1; Neuroectodermal Tumors, Primitive; Sarcoma, Ewing; Sarcoma, Synovial; Spectral Karyotyping; Spinal Cord; Spinal Cord Neoplasms; Vimentin

More than 85% of Ewing sarcoma/primitive neuroectodermal tumor (ES/PNET), or "Ewing family of tumors" (EFTs), have the translocation, t (11;22) (q24;q12), with others having variant translocations. Identification of these by cytogenetic and/or molecular genetic techniques is specific for EFT and is increasingly recognized as the "gold standard" for diagnosis. However, these techniques are not universally available. We therefore studied a large group of genetically confirmed EFTs to more completely understand the morphologic and immunophenotypic spectrum of this rare sarcoma. Sixty-six cytogenetically, FISH or RT-PCR proven-EFTs were retrieved. In 56 cases, immunohistochemistry (IHC) was performed for pan-cytokeratins (PanCK), high molecular weight cytokeratins (HMWCK), desmin (DES), CD99, CD117, and FLI1 protein using heat-induced epitope retrieval and the Dako Envision system. The cases arose chiefly in children and young adults (median 18 years; range, 3-65 years) of both sexes (male, 32; female, 31; unknown, 3) in a variety of bone (N = 39) and soft tissue (N = 27) sites. Histologically, 46 cases (73%) showed only typical features of ES, 9 cases (16%) showed features of PNET, 3 cases (5%) showed "adamantinoma-like" features, 3 cases (5%) corresponded to "atypical Ewing sarcoma," 3 cases (5%) showed principally intersecting fascicles of spindled cells, and 2 cases had abundant hyalinized matrix. IHC results were as follows: PanCK (18 of 56, 32%), HMWCK (3 of 55, 5%), DES (1 of 56, 2%), CD99 (52 of 52, 100%), CD117 (13 of 54, 24%), and FLI1 (44 of 47, 94%). HMWCK was expressed only in "adamantinoma-like" EFTs, none of which expressed DES. In conclusion, most, but not all, EFTs can be accurately diagnosed using time-honored morphologic criteria and ancillary immunohistochemistry. However, genetic confirmation remains essential for the diagnosis of unusual morphologic variants of EFT, including "adamantinoma-like," spindled, sclerosing, and clear cell/anaplastic variants. Therefore, to exclude or confirm the diagnosis of Ewing's sarcoma in round cell sarcomas having a variety of patterns but not specifically conforming to a tumor of known lineage (eg, rhabdomyosarcoma), cytogenetics, and/or molecular analysis is required.

Topics: 12E7 Antigen; Adolescent; Adult; Aged; Antigens, CD; Cell Adhesion Molecules; Child; Child, Preschool; Desmin; Female; Gelsolin; Humans; Immunophenotyping; Keratins; Male; Microfilament Proteins; Middle Aged; Proto-Oncogene Proteins c-kit; Receptors, Cytoplasmic and Nuclear; Sarcoma; Sarcoma, Ewing; Trans-Activators; Translocation, Genetic

Desmoplastic small cell tumor (DSCT) is a distinct type of small blue cell tumors and is characterized by the unique karyotypic aberration involving the fusion of the Ewing's sarcoma (EWS) gene and Wilms' tumor (WT1) gene. Typically, it grows along serosal surfaces; however, in some cases, the tumor presents as a dominant mass in an internal organ. Examples of DSCT forming a primary mass in ovary, testes, and brain have been described, but its presentation as a primary pancreatic mass has not been reported previously. The case reported here is a 31-year-old woman who presented with a 14-cm mass in the pancreas. There were smaller nodules on the peritoneal surfaces that were regarded clinically as metastasis from a primary pancreatic tumor. During the frozen section, the diagnosis of a poorly differentiated endocrine carcinoma of pancreatic origin was rendered and patient underwent subtotal pancreatectomy. On microscopic examination, the tumor was composed of large nests and broad bands of small blue cells, separated by fibrous stroma. Immunohistochemical stains showed positivity of the tumor cells for cytokeratins (AE1:AE3 and CAM5.2), neuron specific enolase, desmin and WT1, whereas chromogranin, S-100, and CD99 were negative. Since this immunoprofile is characteristic of DSCT, molecular analysis was performed which revealed the presence of EWS-WT1 gene fusion characteristic of DSCT. This case shows that in addition to primary pancreatic tumors characterized by prominent cellularity such as solid pseudopapillary tumors, acinar cell carcinoma, pancreatoblastoma, endocrine tumors, and other small blue cell tumors, the differential diagnosis of cellular, stroma-poor neoplasia in the pancreas also includes DSCT. This case is also another demonstrative example of how DSCT may form a dominant mass in intraabdominal organs.

Topics: 12E7 Antigen; Adult; Antigens, CD; Artificial Gene Fusion; Cell Adhesion Molecules; Chromogranins; Female; Humans; Immunohistochemistry; Keratins; Pancreatic Neoplasms; Phosphopyruvate Hydratase; S100 Proteins; Sarcoma, Ewing; Sarcoma, Small Cell; WT1 Proteins

Ewing's sarcoma/primitive neuroectodermal tumor (ES/PNET) is an extraordinarily rare primary tumor in the kidney and can be mistaken for a variety of other round cell tumors, including blastema-predominant Wilms' tumor (WT). Approximately 90% of ES/PNET have a specific t(11;22), which results in a chimeric EWS-FLI-1 protein. Immunohistochemistry for the carboxy-terminus of FLI-1 is sensitive and highly specific for the diagnosis of ES/PNET. WT-1, the WT-associated tumor suppressor gene, is overexpressed in WT but not in ES/PNET. No study has examined FLI-1 or WT-1 expression in renal ES/PNET. The clinicopathologic features of 11 renal ES/PNET were studied along with immunohistochemistry for cytokeratin, desmin, CD99, FLI-1, and WT-1. WT were also immunostained for CD99 (5 cases), FLI-1 (10 cases), and WT-1 (9 cases). The patients (6 men, 5 women) ranged from 18 to 49 years of age (mean, 34 yr). The mean tumor size was 11.8 +/- 3.8 cm (mean +/- standard deviation). Presenting symptoms included abdominal/flank pain and/or hematuria. Grossly, all tumors showed necrosis and hemorrhage, and 4 had cystic change. Microscopically, all tumors showed vaguely lobular growth, primitive round cells, and variable rosette formation. Epithelial, myogenous, or cartilaginous differentiation was not seen. Immunohistochemical results on the renal ES/PNET were cytokeratin (2/8 focal), desmin (0/9), CD99 (8/8), FLI-1 (5/8), and WT-1 (0/8). In comparison, the WT only rarely expressed CD99 (1/5) and did not express FLI-1 (0/10), but were usually WT-1-positive (7/9). Follow-up on 8 cases (mean, 28 mo; range, 6-64 mo) showed 4 lung and pleural metastases, 1 bone metastasis, liver metastasis, 2 local recurrences, and 5 deaths from disease (median time to death, 16.8 mo). No case had distant metastatic disease at presentation. Adjuvant therapy included chemotherapy (8 cases), radiation (3 cases), and bone marrow transplantation (1 case). Our study affirms a unique proclivity of renal ES/PNET for young adults and that it is a highly aggressive neoplasm, with rapid death in many cases, usually after the development of treatment-resistant lung metastases. These tumors must be distinguished from blastema-predominant WT and other primitive renal tumors that require different therapy. FLI-1 and WT-1 immunohistochemistry may be valuable in this differential diagnosis, given the known immunophenotypic overlap between ES/PNET and blastema-predominant WT with regard to CD99, cytokeratin, and

Topics: 12E7 Antigen; Adult; Aged; Antigens, CD; Cell Adhesion Molecules; Child; Combined Modality Therapy; Desmin; Diagnosis, Differential; DNA-Binding Proteins; Female; Genes, Tumor Suppressor; Humans; Immunohistochemistry; Keratins; Kidney Neoplasms; Male; Middle Aged; Neoplasm Metastasis; Neuroectodermal Tumors, Primitive; Proto-Oncogene Protein c-fli-1; Proto-Oncogene Proteins; Sarcoma, Ewing; Trans-Activators; Wilms Tumor; WT1 Proteins

Topics: Adult; Biomarkers, Tumor; DNA, Neoplasm; Female; Humans; Immunohistochemistry; Keratins; Male; Neoplasm Proteins; Neoplasms, Multiple Primary; Neuroectodermal Tumors, Primitive; Oncogene Proteins, Fusion; Proto-Oncogene Protein c-fli-1; Reverse Transcriptase Polymerase Chain Reaction; RNA-Binding Protein EWS; Sarcoma, Ewing; Transcription Factors

Ewing's sarcoma (ES) and primitive neuroectodermal tumor (PNET) are characterized by the presence of the specific t(11;22)(q24;q12) or variants thereof, producing diagnostic EWS fusion transcripts. Cytokeratin has been reported sporadically to be expressed in some cases of ES/PNET. However, its prevalence has not been assessed systematically in a series of cases with confirmatory molecular or cytogenetic evidence of a diagnostic translocation. We present in detail three index patients in whom strong cytokeratin immunoreactivity was a confounding factor in the diagnosis. To establish further the prevalence of cytokeratin immunoreactivity in a series of well-characterized ES/PNET, we then performed immunohistochemical studies with antibodies CAM5.2 and AE1/AE3 on 50 cases of ES/PNET diagnosed at Memorial Sloan-Kettering Cancer Center in which molecular evidence of a specific ES/PNET-associated translocation were available. Immunoreactivity to cytokeratin was present in 10 cases (20%), in five diffusely and five focally. There was no significant association between cytokeratin expression and the following parameters: patient age, sex, skeletal and extraskeletal primary site, and the type of EWS fusion transcript. Cytokeratin expression, a manifestation of epithelial differentiation, is present in as many as 20% of ES/PNET in either a diffuse or focal pattern.

Topics: Adult; Aged; Child; Female; Humans; Immunohistochemistry; Keratins; Male; Neoplasms, Multiple Primary; Neuroectodermal Tumors, Primitive; Sarcoma, Ewing

Topics: Biomarkers, Tumor; Diagnosis, Differential; Humans; Immunohistochemistry; Keratins; Neuroectodermal Tumors, Primitive; Sarcoma, Ewing

Primitive neuroectodermal tumor (PNET), the second most common type of sarcoma in the first two decades of life, rarely presents as an organ-based neoplasm. Rather, it is seen typically in the soft tissues of the chest wall and paraspinal region. We report a case of primary PNET of the kidney in a 17-year-old girl who presented with abdominal pain, hematuria, and an abdominal mass. Nodules and sheets of monotonous-appearing primitive round cells and the formation of rosettes focally were the principal microscopic features. The tumor cells were uniformly immunoreactive for vimentin, cytokeratin, neuron-specific enolase, and 013 (CD99). In addition, the characteristic translocation of PNET and Ewing sarcoma, t(11;22)(q24;q12), was detected by polymerase chain reaction (PCR). Eight previous examples of renal PNET have been reported in the literature in the past 2 years, but only three of these cases have had complete immunohistochemical evaluation with the demonstration of 013 positivity. To our knowledge the present case is the only one to date demonstrating the recurrent translocation t(11;22)(q24;q12) by PCR. Assuming that the previous cases in the literature are bona fide examples of PNET, the kidney may be another site of predilection for this usual soft-tissue neoplasm. We are once again confronted with the dilemma about the nature of the progenitor cell.

Topics: 12E7 Antigen; Adolescent; Antigens, CD; Cell Adhesion Molecules; Combined Modality Therapy; Female; Humans; Keratins; Kidney Neoplasms; Neuroectodermal Tumors, Primitive; Phosphopyruvate Hydratase; Polymerase Chain Reaction; Sarcoma, Ewing; Tomography, X-Ray Computed; Translocation, Genetic; Vimentin

We report an intra-abdominal round cell tumor in a young man which exhibited the light and electron microscopic appearance of a peripheral primitive neuroectodermal tumor (PNET), in addition to the clinical and topographic characteristics, desmoplasia and a complex immunophenotypic profile of the intra-abdominal desmoplastic round cell tumor (DSRCT). Reverse transcription polymerase chain reaction revealed a EWS/FLI-1 fusion transcript as in PNET/Ewing's sarcoma, instead of the EWS/WT1 transcript of DSRCT. The tumor was also strongly positive for the mic2 protein. This is a unique case of a hybrid tumor arising in the peritoneal cavity of a young male. The existence of such a hybrid tumor in this location suggests that DSRCT and PNET may be related and possibly share a common histogenesis.

Topics: Abdominal Neoplasms; Adult; Biomarkers; Blotting, Western; Carcinoma, Small Cell; Desmin; DNA-Binding Proteins; Fatal Outcome; Humans; Immunohistochemistry; Keratins; Male; Microscopy, Electron; Neuroectodermal Tumors, Primitive; Oncogene Proteins, Fusion; Polymerase Chain Reaction; Proto-Oncogene Protein c-fli-1; Proto-Oncogene Proteins; Sarcoma, Ewing; Tomography, X-Ray Computed; Trans-Activators

Seventy-nine cases of small round cell tumors involving bone were studied in an attempt to learn whether the immunohistochemical features of the lesions might allow distinction of small cell osteosarcoma from other potential differential diagnostic considerations, including Ewing's sarcoma, atypical Ewing's sarcoma, primitive neuroectodermal tumor, mesenchymal chondrosarcoma, lymphoma, and the Askin tumor. The tissues studied were all formalin-fixed, decalcified, paraffin sections from patients between the ages of 16 and 48 years. With one exception (a small cell osteosarcoma), none of the lesions was cytokeratin positive. Moreover, none of the lesions was epithelial membrane antigen, desmin, factor VIII-related antigen, synaptophysin, or Leu-M1 positive. Accordingly, strong positivity for these antibodies in a majority of tumor cells should prompt inclusion of tumor types other than those listed above in the differential diagnosis. Vimentin positivity was seen in a majority of the tumors studied irrespective of histologic type. Scattered tumor cells (< 25%) showed positivity with antibodies to muscle-specific actin and smooth muscle actin in several of the different tumor types studied. No lesions other than lymphoma were leukocyte-common antigen (LCA) positive; all but two lymphomas were LCA positive, while all but one lymphoma were L26 positive. One (lymphoblastic) lymphoma was LCA and L26 negative. S-100, neuron-specific enolase, and Leu-7 did not prove to be specific for "neural-associated" tumors, but rather appeared in some small cell osteosarcomas, Ewing's sarcomas, atypical Ewing's sarcomas, primitive neuroectodermal tumors, mesenchymal chondrosarcomas, lymphomas, and Askin tumors. Antibody to cell surface antigen HBA71 was positive in three Ewing's sarcomas (two typical and one atypical) and negative in small cell osteosarcoma (three cases), mesenchymal chondrosarcoma (two cases), and lymphoma (one case). While some guidance may be derived from analysis of immunohistochemical staining patterns in a given lesion, the results reported in the present study do not suggest that routine immunohistochemistry alone will permit distinction of these small cell tumors of bone from one another. The value of immunohistochemical studies appears to lie particularly in the use of antibodies to LCA and S-100 protein to distinguish lymphoma and mesenchymal chondrosarcoma, and perhaps antibody to HBA71 to distinguish neural family lesions (such as Ewing's sarcoma)

Topics: Adolescent; Adult; Antigens, Differentiation; Bone Neoplasms; Chondrosarcoma, Mesenchymal; Desmin; Diagnosis, Differential; Humans; Immunohistochemistry; Keratins; Leukocyte Common Antigens; Lymphoma; Membrane Glycoproteins; Middle Aged; Mucin-1; Osteosarcoma; S100 Proteins; Sarcoma, Ewing; Sarcoma, Small Cell; Synaptophysin; von Willebrand Factor

The histogenesis of Ewing sarcoma is still controversial; we therefore studied the expression of intermediate filaments (IF) in cell lines derived from Ewing tumors since identification of IF in tumor cells is considered a reliable marker of tissue origin and differentiation. All nine lines studied expressed vimentin IF; in addition, a small number of Ewing cells from three lines expressed keratin filaments. After treatment with phorbol esters, a high percentage of cells from these three lines synthesize keratin IF identified by immunoblotting as keratin 8 and 18 polypeptides, which are expressed by single epithelia and epithelial cells in early embryonic development. Furthermore cells from a fourth line synthesize keratins after transplantation in nude mice. These data indicate that, under certain conditions, undifferentiated Ewing cells may acquire an IF phenotype related to that of epithelial cells.

Topics: Animals; Cell Line; Cytoskeleton; Humans; Immunoenzyme Techniques; Intermediate Filaments; Keratins; Mice; Mice, Nude; Neoplasm Transplantation; Sarcoma, Ewing; Tetradecanoylphorbol Acetate

Examples of classical Ewing's tumors ("Ewing's sarcomas") of both skeletal and extraskeletal locations were analyzed for the expression of intermediate filament (IF) and cell junction proteins, with the use of immunofluorescence and immunoelectron microscopy as well as gel electrophoresis. In all 11 tumors examined vimentin filaments were abundant. A type of plaque-bearing small cell junction, which is common in these tumors but difficult to classify by morphologic criteria, was identified by antibodies to desmoplakins as true desmosomes. These were found in all cases, although in a very variable proportion of cells. Some of these junctions were associated with vimentin IFs. In addition, 9 of the cases examined showed scattered or clustered cells expressing the simple-epithelium type cytokeratins 8 and 18. Moreover, 3 cases displayed dispersed or clustered cells producing neurofilaments. The value of these observations, notably the cell type heterogeneity, for the diagnosis of tumors of this group is discussed. The results further indicate that Ewing's tumors are derived from a primitive, pluripotential cell that may differentiate, in variable proportions, into cells with mesenchymal, epithelial, and, more rarely, even neural features, suggesting that this tumor should be regarded as a blastoma, rather than as a true sarcoma.

Topics: Adolescent; Adult; Cell Differentiation; Child; Cytoskeletal Proteins; Cytoskeleton; Desmosomes; Electrophoresis, Polyacrylamide Gel; Female; Histocytochemistry; Humans; Intercellular Junctions; Intermediate Filaments; Keratins; Male; Microscopy, Electron; Phosphopyruvate Hydratase; Sarcoma, Ewing; Vimentin