Histologic features of urothelial carcinomas involving the upper urinary tract are similar to the tumors seen in the urinary bladder. However, papillary urothelial neoplasm of low malignant potential and low-grade carcinomas are seen less frequently in the upper urinary tract. Almost 70% of cases have high-grade features. The image shows low grade papillary urothelial carcinoma. There is no evidence of invasion. The base of the tumor is smooth, broad-based and does not have jagged infiltrating margins.