title: Endometrial endometrioid carcinomas associated with Ewing sarcoma/peripheral primitive neuroectodermal tumor.
abstract: Three uterine tumors, each consisting of endometrioid carcinoma and Ewing's sarcoma/peripheral primitive neuroectodermal tumor (ES/pPNET) are described. The diagnosis of ES/pPNET in each case was first established in the hysterectomy specimen because each ES/pPNET was misinterpreted on the endometrial biopsy specimens as a high-grade homologous sarcoma. The ES/pPNET element in each case consisted of solid masses of small- to medium-sized round cells without Homer-Wright pseudorosettes, glial or ganglion cells, true rosettes with central lumens, or medulloepithelial tubules. Each ES/pPNET exhibited focal positive immunostaining for neuron-specific enolase, diffuse staining for vimentin, and strong cell membrane immunoreactivity for O13 (CD99), the last finding providing the first clue to the diagnosis of ES/pPNET in each case. The diagnosis in each case was confirmed by detection of EWS/FLI-1 fusion transcript through reverse transcription polymerase chain reaction. We also examined O13 immunoreactivity retrospectively in 40 cases of malignant mixed mullerian tumors (MMMT) with homologous or heterologous elements. O13 immunoreactivity was not observed in the malignant epithelium or in the homologous or heterologous sarcomas. The immunoreactivity of O13 in round cell endometrial sarcomas provides a clue to the diagnosis of ES/pPNET.
authors.affiliation: Department of Pathology, University of Texas Southwestern Medical Center, Dallas 75235-9073, USA.
authors.forename: P
authors.initials: P
authors.lastname: Sinkre
authors.forename: J
authors.initials: J
authors.lastname: Albores-Saavedra
authors.forename: D S
authors.initials: DS
authors.lastname: Miller
authors.forename: L J
authors.initials: LJ
authors.lastname: Copeland
authors.forename: A
authors.initials: A
authors.lastname: Hameed
mesh_terms: D000071443:12E7 Antigen; D000368:Aged; D015703:Antigens, CD / Q000032:analysis; D018269:Carcinoma, Endometrioid / Q000175:diagnosis* / Q000473:pathology; D015815:Cell Adhesion Molecules / Q000032:analysis; D016889:Endometrial Neoplasms / Q000175:diagnosis* / Q000473:pathology; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008875:Middle Aged; D018200:Mixed Tumor, Mullerian / Q000175:diagnosis / Q000473:pathology; D017599:Neuroectodermal Tumors / Q000175:diagnosis* / Q000473:pathology; D015514:Oncogene Proteins, Fusion / Q000235:genetics; D051789:Proto-Oncogene Protein c-fli-1; D012333:RNA, Messenger / Q000032:analysis; D034802:RNA-Binding Protein EWS; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012512:Sarcoma, Ewing / Q000175:diagnosis* / Q000235:genetics / Q000473:pathology; D014157:Transcription Factors / Q000235:genetics; D014594:Uterine Neoplasms / Q000175:diagnosis / Q000473:pathology
chemical_list: D000071443:12E7 Antigen; D015703:Antigens, CD; C061828:CD99 protein, human; D015815:Cell Adhesion Molecules; C106031:EWS-FLI fusion protein; D015514:Oncogene Proteins, Fusion; D051789:Proto-Oncogene Protein c-fli-1; D012333:RNA, Messenger; D034802:RNA-Binding Protein EWS; D014157:Transcription Factors