Outcomes of invasive melanoma of the head and neck treated with Mohs micrographic surgery e A multicenter study

Background: There are no randomized controlled trials to guide surgical margins for invasive head and neck (H & N) melanoma using conventional excision. Mohs micrographic surgery (MMS) has shown improved local recurrence rates and survival for invasive H & N melanomas. Objective: Determine local recurrence (LR), nodal recurrence, and distant recurrence rates, and disease specific survival for invasive melanoma of the H & N treated with MMS. Methods: A retrospective multicenter study of 785 cases of invasive H & N melanoma treated with MMS using frozen sections with melanoma antigen recognized by T-cells 1 immunohistochemical staining was performed to evaluate long-term outcomes over 12-years. Results: 785 melanomas (thickness: 0.3 mm-8.5 mm) were treated with MMS. LR, nodal recurrence, and distant recurrence rates were 0.51% (4/785), 1.0% (8/785), and 1.1% (9/785) respectively. For T1, T2, T3, and T4 tumors LR was 0.16% (1/636), 1.18% (1/85), 2.22% (1/45), and 5.26% (1/19), respectively. Five and 10-year disease specific survival were 96.8% (95% CI 95.0% to 98.5%) and 93.4% (95% CI 88.5% to 98.3%). Limitations: A nonrandomized retrospective study. Conclusion: MMS achieves significant improvements in LR compared to a meta-analysis of historical cohorts of patients treated with conventional excision. MMS should be considered an important surgical option for invasive H & N melanoma. ( J Am Acad Dermatol 2023;89:544-50.)