Margin Size for Unique Skin Tumors Treated With Mohs Micrographic Surgery: A Survey of Practice Patterns

Mohs micrographic surgery (MMS) has shown lower recurrence rates for unique skin tumors compared with wide local excision, but there is a lack of standardization on margin size. We aimed to assess MMS practice patterns of margin sizes for unique skin tumors. A survey was distributed to members of the American College of Mohs Surgery (ACMS). Demographic information on participants was collected in addition to initial/subsequent MMS margin size for unique skin tumors, including dermatofibrosarcoma protuberans (DFSP), atypical fibroxanthoma (AFX), melanoma, sebaceous carcinoma, microcystic adnexal carcinoma (MAC), poorly differentiated squamous cell carcinoma (SCC), and Merkel cell carcinoma. Eighty-seven respondents completed the survey (response rate <10%). Given that no guidelines exist on MMS margins for less commonly treated skin tumors, this study helps give Mohs surgeons perspective on current practice patterns for margin sizes. Mohs surgeons are more likely to take larger initial margins for these common skin tumors compared with BCCs or SCCs.