[Hereditary non polyposis colorectal cancer].

Hereditary non polyposis colorectal cancer (HNPCC) is characterized by an excess of early colorectal carcinomas, preferentially located on the ascending colon, associated with a variety of extracolonic cancers. The recent demonstration of germline mutations in DNA mismatch repair genes in HNPCC patients enhanced the interest due to the syndrome. Molecular genetic testing of HNPCC has become available, and should help physicians to recommend specific modalities for the surveillance and the management of patients with such a high cancer risk.