DNA mismatch repair protein expression and microsatellite instability in primary mucosal melanomas of the head and neck

Abstract

Expression of hMSH2 and hMLH1 proteins was up-regulated in three cases, whereas in two cases that of hPMS2 was increased. hMSH6 expression was comparable to that of normal cells in all cases. The percentage of positive neoplastic cells and the intensity of staining seemed to be greater in pleomorphic melanomas. Six cases were MMR-proficient and microsatellite stable.