Synchronous inverted papilloma of bladder and renal pelvis.

Inverted papilloma of the urinary tract is a rare tumor that consists of uniform urothelial cells with an inverted configuration and a normal urothelial lining. Despite several published reports, the prognostic significance and the potential biologic behavior remain uncertain. We detail a case of synchronous inverted papilloma of the urinary bladder and the renal pelvis and review the published data.