A case of monophasic synovial sarcoma presenting as a vulvar mass.

Background: Synovial sarcoma is the fourth most commonly occurring sarcoma, accounting for 8-10% of all sarcomas. They arise from unknown pleuripotent stem cells that are capable of differentiating into mesenchymal and/or epithelial structures. Synovial sarcoma is characterized by specific chromosomal translocation t (X; 18)(p11, q11).