Urothelial Carcinoma of Renal Pelvis
Urothelial carcinomas of the renal pelvis arise in the lining of the pelvicalyceal system. They make up about 7% of all primary renal carcinomas. Several risk factors have been identified, including tobacco smoking, long-term analgesic use (phenacetin), Balkan nephropathy, and occupational exposure to petrochemicals, coal, tar, and asphalt. Horshoe kidney, cyclophosphamide therapy, and exposure to Thorotrast are additional risk factors. Almost two-thirds of patients have prior or concurrent tumors elsewhere in the urinary tract, usually in the bladder. The image shows a large polypoid mass projecting into the pelvicalyceal system.