Ultraviolet-assisted punch biopsy mapping for lentigo maligna melanoma

Lentigo maligna melanoma (LMM) accounts for a substantial incidence of all locally recurrent melanoma. In addition, the head and neck area accounts for 60% to 90% of all LMMs, which has important functional and cosmetic implications. The difficulty in the identification of the true borders of LMM may account for the high incidence of local recurrence. The purpose of this study was to evaluate the efficacy of ultraviolet-assisted punch biopsy mapping to identify clear margins using identified, 2-mm circumferentially arranged punch biopsies at the junction of the pigmented and nonpigmented borders. A retrospective chart review of 20 patients with biopsy-confirmed LMM of the head and neck was performed. Using ultraviolet identification, 2-mm circumferentially arranged biopsy specimens were obtained and sent for formal pathological review, including immunohistochemical staining. The average time for completion of pathological review was 5 to 7 days. If the punch biopsies were positive for lentigo maligna or LMM, punch biopsies were obtained more peripherally. Once clear, margins were obtained and definitive resection was performed. Twenty patients with biopsy-proved LMM were evaluated. Follow-up ranged from 6 months to 3 years (mean follow-up, 1 year). Fourteen patients were cleared after their first series of biopsies, 3 patients required a second series of biopsies, 2 patients required a third session, and 1 patient required a fourth biopsy session. To date, there has been no evidence of recurrence. No patients required reexcision for positive surgical margins. One complication has been local cellulitis of a punch biopsy site requiring a short course of antibiotics. Ultraviolet-assisted punch biopsy mapping of LMM is a safe, well-tolerated, and accurate technique for identifying the true histological margin of LMM. The procedure reduces the need for repeat surgical excisions to obtain clear margins and may decrease the risk for recurrence by mapping accurately the true histological margin.