Dermatofibrosarcoma protuberans (DFSP) is a rare neoplasm derived from fibroblasts. Although the frequency of microsatellite instability (MSI) in skin cancer is reported to be less than 5%, there is only one report of the status of MMR in DFSP. The only analytical report of microsatellite stability in which Promega panel is not used, showed that the frequency of MSI-high, MSI-low and microsatellite stable (MSS) cases was 13.9% (5/36), 16.7% (6/36) and 69.4% (25/36), respectively. Thus, the aim of this study was to evaluate the status of MMR in 36 patients with DFSP diagnosed at Kumamoto University. MSI analysis using the Promega panel showed that all cases were MSS, which indicated the absence of MSI in DFSP. This result indicates that the status of MMR may not be useful for the potential therapeutic application of pembrolizumab and the pathogenesis of DFSP may not involve MSI.
Keywords: dermatofibrosarcoma protuberans (DFSP); microsatellite instability (MSI).