Renal Cell Carcinoma Invading the Urinary Collecting System: Implications for Staging

Purpose: Current TNM staging of renal cell carcinoma is based on the tumor propensity for local extension (T), nodal involvement (N) and metastatic spread (M). Locally advanced renal cell carcinoma may involve the perirenal fat, adrenal glands, renal vein, vena cava and/or urinary collecting system. The existing TNM classification does not reflect the ability of renal cell carcinoma to invade the urothelium. We evaluated the incidence and characteristics as well as overall and cancer specific survival of renal cell carcinoma invading the urinary collecting system.Methods and Materials: We reviewed pathological findings in 504 kidneys from 475 patients with renal cell carcinoma who presented to our institution in a 3-year period. Urothelial involvement required evidence of gross or histological invasion of the renal calices, infundibulum, pelvis or ureter. Demographic and survival data were obtained from medical records and an institutional cancer registry for tumors invading the urothelium. Stage specific...