Urothelial tumors of the renal pelvis and ureters (upper urinary tract) are relatively rare. Tumors of the renal pelvis account for approximately 10% of all renal tumors and only 5% of all urothelial tumors of the urinary tract. Ureteral tumors occur about one half as often as tumors located in the renal pelvis. Transitional cell carcinoma (TCC) accounts for more than 95% of urothelial tumors of the upper urinary tract.