Renal pelvic urothelial carcinoma in horseshoe kidney.

A 40-year-old man with asymptomatic gross hematuria visited our hospital. He had been followed up on the horseshoe kidney and left ureteral stone. Cystoscopy revealed a flow of gross hematuria from the left orifice. Drip infusion pyelography, retrograde pyelography, abdominal computerized tomography, magnetic resonance imaging revealed a renal pelvic mass in the upper pole of left kidney. Left nephroureterectomy and isthmusectomy and partial cystectomy were done. A microwave tissue coagulator (Microtaze AZM-520, AZWELL) was used to divide the isthmus. There was very little bleeding and leakage of urine from the divided isthmus. The postoperative course was favorable.