Urothelial neoplasms of the kidney and ureter. An epidemiologic, pathologic, and clinical review.

Urothelial neoplasms occur with varying frequency at different sites along the urothelial tract. Approximately 5% of urothelial neoplasms occur in the kidneys and ureters, while the majority of these tumors occur in the urinary bladder. Consequently, urothelial disease of the bladder has been evaluated to a greater extent than urothelial tumors elsewhere, and many of the features of bladder urothelial neoplasms have been applied to these tumors at other sites. While the classification of urothelial neoplasms is the same for tumors in the bladder, kidney, and ureter, there are some features of urothelial neoplasms of the kidney and ureter that are unique to these sites. An epidemiologic, pathologic, and clinical review of urothelial neoplasms of the kidney and ureter is presented.