Primary renal synovial sarcoma

Primary renal synovial sarcoma is a rare tumor, with a poor prognosis which must be differentiated from other renal tumors. We report a new case of renal synovial sarcoma in a 60 year-old man. Histologic examination showed a proliferation of monomorphic spindle cells arranged in fascicles with hemangiopericytomatous pattern. Tumor cells were immunoreactive for bcl2, CD99, cytokeratin and epithelial membrane antigen. The diagnosis of spindle cell type monophasic synovial sarcoma was proposed and confirmed by fluorescence in situ hybridization. Patient was treated with chemotherapy. He developed bone and liver metastasis and died 7 months after nephrectomy. The diagnosis of renal synovial sarcoma is based on histological and immunohistochemical studies and must be confirmed by molecular techniques which showed the translocation t (X; 18).