Mohs surgery for the treatment of melanoma in situ: a review.

BACKGROUND: Controversy exists in the literature regarding the use of Mohs surgery for the treatment of melanoma in situ (MIS). Mohs surgery provides the advantage of complete margin assessment; however, variations in surgical and laboratory techniques employed, make comparison of outcomes difficult. OBJECTIVE: To review the current literature regarding Mohs surgery for treatment of MIS and to evaluate treatment options. METHODS: We review the literature regarding traditional excision margins for MIS, the proportion of biopsy-proven MIS lesions that prove to have an invasive component, and the efficacy of Mohs surgery for MIS. RESULTS: Many authors report a need for surgical margins larger than the recommended 5 mm, particularly with MIS arising in sun-exposed areas. Further, a review of the literature reveals that nearly one-quarter of biopsy-proven MIS lesions are found to contain invasive melanoma after complete surgical removal and pathologic examination. Substantial evidence supports the value of complete margin assessment in the treatment of MIS, particularly in the head and neck region. CONCLUSION: Complete surgical excision with careful margin assessment is required to adequately treat MIS lesions, particularly given the high rate of invasive melanoma in lesions initially thought to be MIS. Mohs surgery remains the treatment of choice for all clinically ill-defined MIS.