Primary Ewing Sarcoma of Vulva: A Case Report and a Review of Literature

Ewing sarcoma family of tumour represents a group of bone and soft-tissue tumours with variable neuroectodermal differentiation. Extraosseous Ewing sarcoma (EES) commonly arises in soft tissues of trunk or extremities with a few reported rare sites include larynx, nasal cavity, neck, lung, retroperitoneum, mediastinum and genital tract. Till now 28 cases of extraosseous Ewing sarcoma of vulva and vagina have been reported in the literature. We report 29th case of Ewing sarcoma vulva in sixth youngest, 16-year-old patient with third largest size tumour. Her all routine blood reports were found to be normal, and MRI showed highly vascular vulval mass with terminal urethral involvement. Tru-cut biopsy revealed uniform sheets of small round cells with geographical necrosis and perivascular clusters of tumour cells. Immunohistochemical staining demonstrated that the cells were focally positive for CK and vimentin and showed membranous positivity for CD99 and nuclear positivity for FLI1, whereas all other IHC markers to rule out differentials of small round cell tumour were negative. Based on HPE and IHC, which is polyimmunophenotypic, has confirmed the diagnosis of an ES/PNET. After ruling out for the metastatic lesions, 14 cycles of chemotherapy with compressed VDC/IE were planned, but after receiving her 1st cycle itself, she expired on 10th day of post-chemotherapy. EES is a rare fast growing aggressive tumour requiring ancillary techniques for exact diagnosis and multimodality treatment for better survival.