Xanthogranulomatous pyelonephritis associated with renal cell carcinoma. Report on two cases and review of the literature.

Xanthogranulomatous pyelonephritis is a rare and particularly aggressive variant of chronic destructive pyelonephritis. Even when all modern diagnostic possibilities are exhausted, it is often not possible to distinguish xanthogranulomatous pyelonephritis from a renal cell carcinoma preoperatively. In clinical practice false diagnoses are therefore frequent. The coexistence of xanthogranulomatous pyelonephritis and renal cell carcinoma is extremely rare. We report 2 such cases. In 1 case surgery was performed on the kidney affected by xanthogranulomatous pyelonephritis using a renal sparing technique.