A case of inverted papilloma of the renal pelvis, associated with metachronous urothelial carcinoma of the urinary bladder

The patient visited our hospital because of macrohematuria. Cystoscopical examination did not reveal any bladder tumors but a tumor shadow in the right renal pelvis was revealed by computed tomographic scan. Urothelial carcinoma was suspected and right nephroureterectomy was performed. Pathologically the tumor was diagnosed as inverted papilloma. Four months later during the follow up of the tumor, urothelial carcinoma of the urinary bladder was detected by cystoscopy. Inverted papilloma of the renal pelvis is a rare lesion and only 39 cases to date have been reported. Because inverted papilloma of the upper urinary tract is often associated with other urothelial tumors, careful long-term follow up is advisable.