[Two cases of bladder cancer with hereditary nonpolyposis colorectal cancer].

Hereditary nonpolyposis colorectal cancer (HNPCC) is an autosomal dominant disorder characterized by an excess of extracolonic malignancies including those of the urinary tract. We report two cases of bladder tumor associated with HNPCC. The reported cases were compatible for Amsterdam criteria II for HNPCC. It is important to obtain a family history of cancer in patients with urothelial carcinoma. A patient with a strongly positive cancer history must be carefully examined for HNPCC and HNPCC associated cancers.