Primary renal synovial sarcoma

Synovial sarcomas (SSs) are very rare, poorly studied tumors that generally occurs around joint and muscle tendons. Primary SSs of the kidney are even rarer, accounting for <2% of all malignant renal tumors. We report the case of a 44-year-old man who was diagnosed with primary renal SS on the basis of imaging, histopathological, and immunohistochemical examination. We also present a comprehensive review of the literature, with a focus on the differential diagnosis and treatment of renal tumors.