title: Primary Ewing's sarcoma-primitive neuroectodermal tumor of the vagina.
abstract: BACKGROUND
  Only three cases of Ewing's sarcoma-primitive neuroectodermal tumor (ES-PNET) occurring in the vagina have been previously reported.
  
  
  METHODS
  A 30-year-old Chinese woman presented with a vaginal mass measuring 5 cm in greatest dimension. The tumor was composed of solid sheets of undifferentiated small round cells with numerous Homer-Wright rosettes. Immunohistochemically, it was positive for CD99, FlI-1 protein, synaptophysin, neuron-specific enolase, vimentin, and S-100 protein. The patient underwent wide local excision of the tumor and subsequent total abdominal hysterectomy with postoperative chemotherapy and radiotherapy. She is disease-free 36 months after the initial surgery.
  
  
  CONCLUSIONS
  This is a rare case of ES-PNET occurring in the vagina and the first showing many distinctive Homer-Wright rosettes. A review of literature indicates that vaginal or vulvar ES-PNET affects younger women, and it may have a relatively favorable outcome.
authors.affiliation: Department of Pathology, Peking University People's Hospital, Beijing 100044, PR China. xiaoyliao@sina.com
authors.forename: Xiaoyun
authors.initials: X
authors.lastname: Liao
authors.forename: Xiuxia
authors.initials: X
authors.lastname: Xin
authors.forename: Xiaohong
authors.initials: X
authors.lastname: Lü
mesh_terms: D000328:Adult; D003131:Combined Modality Therapy; D005260:Female; D006801:Humans; D018241:Neuroectodermal Tumors, Primitive, Peripheral / Q000473:pathology*; D012512:Sarcoma, Ewing / Q000473:pathology* / Q000628:therapy; D014625:Vaginal Neoplasms / Q000473:pathology* / Q000628:therapy