CT findings of synovial sarcomas of the kidney with pathological correlation.

PURPOSE: To describe computed tomography (CT) findings of primary synovial sarcoma of the kidney with pathological correlation. METHODS: CT findings of four cases of pathologically confirmed synovial sarcoma of the kidney were retrospectively viewed and correlated with pathologic features. RESULTS: The four synovial sarcomas presented as soft tissue masses with multiple smooth wall cysts. Pathologically, entrapped and dilated renal tubules formed the smooth wall cysts lined by hobnail tubular epithelium. CONCLUSION: Primary renal synovial sarcoma might manifest as a renal mass with multiple smooth wall cysts. The cysts are consistent with entrapped dilated renal tubular and are lined with hobnail tubular epithelium.