Abstract
The Muir-Torre syndrome (MTS) is a variant of the hereditary nonpolyposis colorectal cancer syndrome (HNPCC). The MTS has to be redefined clinically to include all the potential cutaneous phenotypes of sebaceous neoplasms including keratoacanthoma as the latter, MTS and HNPCC have all been identified with the genetic molecular findings of chromosomal abnormalities of DNA mismatched repair (MMR) sequences. Retrospective pedigree investigations for systemic cancer occurrences and cutaneous stigmata of MTS, followed by gene testing for abnormal DNA MMR, will identify kindreds and their members with high hereditary cancer risks for HNPCC.