Hereditary nonpolyposis colorectal cancer syndrome in a patient with urothelial carcinoma of the upper urothelial tract.

Urothelial carcinoma of the upper urinary tract is relatively uncommon but may develop as a manifestation of the hereditary nonpolyposis colorectal cancer syndrome (HNPCC), which is characterized by mutations in a number of DNA mismatch repair genes and detectable as microsatellite instability or loss of the respective protein by immunostaining. No well-established screening test is available for urothelial carcinomas of the upper urinary tract, and little is known of the clinical impact of screening for HNPCC in patients with upper urinary tract cancer. We describe herein a patient with a urothelial carcinoma of the ureter and a strongly positive history of cancer, who was subsequently found to have HNPCC. Our findings reinforce the importance of obtaining a comprehensive history of cancer in patients with urothelial carcinoma of the renal pelvis and ureter. Subsequent identification of individuals with HNPCC enables the patient and at-risk relatives to benefit from targeted surveillance and management programs.