Renal pelvic urothelial carcinoma with divergent morphology

Compared with that of urinary bladder, urothelial carcinoma of renal pelvis is infrequent and its morphologic features and presentations have seldom been described. Fifty-nine renal pelvic urothelial carcinomas were evaluated in this study. Seventy-eight percent of these were high-grade tumors, of which 39% contained variable amount of divergent morphology. Forty-four percent of the high-grade urothelial carcinomas presented with an advanced tumor stage. Seventy-eight percent of urothelial carcinomas with divergent morphology displayed a tumor stage of pT2 and above, compared with 21% of classical urothelial carcinomas, which presented at stage pT2 and above. In summary, high-grade and unusual morphology as well as advanced tumor stage were the frequent findings in pelvicalyceal urothelial carcinomas. In addition, divergent morphology was correlated with advanced tumor stage. The clinicopathologic features of pelvicalyceal urothelial carcinomas with unusual divergent morphology were particularly emphasized in this study.