Acute retroperitoneal hemorrhage due to transitional cell carcinoma of the renal pelvis.

A young, otherwise healthy man was hospitalized with clinical findings of acute retroperitoneal hemorrhage. Radiographic evaluation suggested a large bleeding renal mass that was thought to be renal cell carcinoma. Radical nephrectomy was performed after angio-embolization. Final pathological diagnosis was grade III transitional cell carcinoma of the renal pelvis invading the renal parenchyma. Distal ureterectomy was subsequently performed 12 days after nephrectomy. Preoperative or intraoperative diagnosis of transitional cell carcinoma would have spared our patient the morbidity of a delayed second procedure. Transitional cell carcinoma of the renal pelvis should be considered in the differential diagnosis of acute retroperitoneal hemorrhage.