title: Primary Ewing sarcoma/peripheral primitive neuroectodermal tumor of the vulva.
abstract: We report a case of Ewing sarcoma/peripheral primitive neuroectodermal tumor (ES/pPNET) arising in the vulva in a 17-year-old adolescent girl. Primary extraskeletal ES/pPNET is uncommon and only rarely affects the female genital tract. Characteristic histologic features of ES/pPNET were present in this case including a monomorphic population of small round blue cells with cytoplasmic glycogen confirmed by periodic acid-Schiff and were immunohistochemically positive for CD99 in a membranous and Fli-1 in a nuclear pattern. The presence of an EWS/Fli-1 fusion transcript was demonstrated by reverse transcription polymerase chain reaction and confirmed by direct sequencing. This report described another very rare case of ES/pPNET arising in the vulva and confirmed by molecular analysis.
authors.affiliation: Department of Pathology, Baylor College of Medicine, Houston, TX 77030, USA.
authors.forename: Y Erika
authors.initials: YE
authors.lastname: Fong
authors.forename: Dolores
authors.initials: D
authors.lastname: López-Terrada
authors.forename: Qihui Jim
authors.initials: QJ
authors.lastname: Zhai
mesh_terms: D000293:Adolescent; D001483:Base Sequence; D014408:Biomarkers, Tumor; D004273:DNA, Neoplasm / Q000032:analysis; D005260:Female; D006003:Glycogen / Q000378:metabolism; D006801:Humans; D008969:Molecular Sequence Data; D009378:Neoplasms, Multiple Primary; D018241:Neuroectodermal Tumors, Primitive, Peripheral / Q000378:metabolism / Q000473:pathology*; D015514:Oncogene Proteins, Fusion / Q000235:genetics / Q000378:metabolism; D010503:Periodic Acid-Schiff Reaction; D051789:Proto-Oncogene Protein c-fli-1; D034802:RNA-Binding Protein EWS; D012512:Sarcoma, Ewing / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D017422:Sequence Analysis, DNA; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D014846:Vulvar Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology*
chemical_list: D014408:Biomarkers, Tumor; D004273:DNA, Neoplasm; C106031:EWS-FLI fusion protein; D015514:Oncogene Proteins, Fusion; D051789:Proto-Oncogene Protein c-fli-1; D034802:RNA-Binding Protein EWS; D014157:Transcription Factors; D006003:Glycogen