Mohs surgery and margin control in the treatment of melanoma

Mohs micrographic surgery (MMS), a surgical and histopathological technique that permits histologic analysis of the entire deep and superficial tumor margin, has been used successfully to treat many types of cutaneous malignancy. MMS results in cure rates as high as 99% for nonmelanoma skin cancer and is particularly useful in areas where standard surgical margins would result in cosmetic and functional deficits. The use of MMS for the treatment of melanoma has been controversial. This controversy stems from the perceived difficulty of diagnosing melanoma in frozen sections and a lack of prospective studies documenting equivalence or superiority to standard wide excision. We review the Mohs technique, detail the challenges facing MMS in the treatment of melanoma and discuss the evidence supporting its use. Despite the challenges, we find evidence of the effectiveness of MMS in the treatment of melanoma, particularly lentigo maligna of the face.