Mohs micrographic surgery may cure the 17% of melanoma in situ (MIS) that exceed traditional excision margins of 5 mm and is a valuable option for these patients, a recent study found. Researchers examined the long-term outcomes in 882 cases of MIS treated with Mohs micrographic surgery, comparing them to historical controls. They found:

• 1 local recurrence occurred in the cohort (0.1%).

• Only 83% of MIS were excised with a 6 mm margin.

• Margins of 9 mm were needed to excise 97% of MIS, statistically equivalent to thin melanomas.

• Surgical margins of least 0.9 cm should be considered for MIS of the trunk and extremities when total margin evaluation is not used.

Citation: Stigall LE, Brodland DG, Zitelli JA. The use of Mohs micrographic surgery (MMS) for melanoma in situ (MIS) of the trunk and proximal extremities. [Published online ahead of print July 26, 2016]. J Am Acad Dermatol. doi:10.1016/j.jaad.2016.06.033.