Primary renal synovial sarcoma with inferior vena cava and right atrium invasion.

Primary renal synovial sarcoma is an uncommon and perhaps under-diagnosed disease. We report a case of renal tumor in a 19-year-old man. Clinically, the tumor mimicked renal cell carcinoma with renal vein, inferior vena cava and right atrium invasion. Histologically, the tumor consisted of monophasic, high-grade, spindle cell components. The diagnosis was validated by fluorescence in situ hybridization and reverse transcription-polymerase chain reaction, which demonstrated SYT-SSX translocation: a characteristic cytogenetic finding for synovial sarcoma. Our case shows that synovial sarcoma should be considered in the differential diagnosis of renal tumors, especially in adolescents and young adults. Proper molecular analysis should be undertaken to attain a definitive diagnosis.