title: Ewing sarcoma with extensive neural differentiation: a clinicopathologic, immunohistochemical, and molecular analysis of three cases.
abstract: OBJECTIVE
  Three patients with Ewing sarcomas showing extensive neural differentiation are presented.
  
  
  METHODS
  The patients were two women and one man between the ages of 15 and 35 years. Anatomically, one tumor was in the lung, one in the testis, and one in the cervix uteri. The symptoms were determined by the location of the neoplasm and included respiratory symptoms, testicular pain, and pelvic manifestations, respectively. Complete surgical resection of the tumors was performed.
  
  
  RESULTS
  Histologically, all neoplasms showed similar characteristics-namely, a neoplastic cellular proliferation arranged in sheets and composed of small blue cells with round to oval nuclei and inconspicuous nucleoli typical for Ewing sarcoma. In addition, in two cases, there were areas characterized by the presence of neuropil, ganglion cells, and small cells most compatible with ganglioneuroblastoma, while in one tumor, the neural component was characterized by the presence of small cells with prominent perivascular pseudorosettes more closely resembling ependymoma. Immunohistochemical studies in all cases and molecular analysis in two tumors were in keeping with a diagnosis of Ewing sarcoma.
  
  
  CONCLUSIONS
  The recognition of such histologic variants is important in the diagnostic assessment of these tumors to avoid misinterpretation, especially in small biopsy specimens.
authors: From the Department of Pathology, The University of Texas MD Anderson Cancer Center, Houston. aweissferdt@mdanderson.org.
authors: Annikka
authors: A
authors: Weissferdt
authors: From the Department of Pathology, The University of Texas MD Anderson Cancer Center, Houston.
authors: Neda
authors: N
authors: Kalhor
authors: From the Department of Pathology, The University of Texas MD Anderson Cancer Center, Houston.
authors: Cesar A
authors: CA
authors: Moran
mesh_terms: D000293:Adolescent; D000328:Adult; D014408:Biomarkers, Tumor / Q000378:metabolism*; D002148:Calmodulin-Binding Proteins / Q000235:genetics; D002454:Cell Differentiation; D003937:Diagnosis, Differential; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D008175:Lung Neoplasms / Q000378:metabolism / Q000473:pathology* / Q000601:surgery; D008297:Male; D034802:RNA-Binding Protein EWS; D016601:RNA-Binding Proteins / Q000235:genetics; D012512:Sarcoma, Ewing / Q000378:metabolism / Q000473:pathology* / Q000601:surgery; D013736:Testicular Neoplasms / Q000378:metabolism / Q000473:pathology* / Q000601:surgery; D002583:Uterine Cervical Neoplasms / Q000378:metabolism / Q000473:pathology* / Q000601:surgery
chemical_list: D014408:Biomarkers, Tumor; D002148:Calmodulin-Binding Proteins; C500986:EWSR1 protein, human; D034802:RNA-Binding Protein EWS; D016601:RNA-Binding Proteins
keywords: Ewing sarcoma; Neural; Sarcoma