RESUMO
Background: Lentigo maligna (LM) is a subtype of melanoma in situ that occurs on sun-damaged skin and is associated with significant subclinical extension beyond the clinical margins of the lesion. Objectives: This study aimed to determine if the standard recommended tumor excision margins for LM are adequate to achieve a 97% clearance rate and if any patient or tumor characteristics warranted wider margins. Methods: This study is a retrospective chart review of all patients who were diagnosed with LM of the head and neck and treated with staged excision. Results: The study included 64 patients. With a 6 mm surgical excision margin, only 60.9% of LM were completely excised. A 9 mm margin resulted in complete clearance of 71.9% of LM cases, and a 12 mm margin resulted in complete clearance in 90.6%. A surgical excision margin of 18 mm would have been required to excise 96.7% of tumors completely. Recurrent tumors (P = .01) and tumor size larger than 20 mm were associated with wider surgical excision margins (P = .154). Conclusion: This study of LM in a South African population corroborates that the standard surgical excision margins recommended by international melanoma guidelines for LM are inadequate to achieve a 97% clearance rate.
RESUMO
BACKGROUND: The American Society for Dermatologic Surgery (ASDS) International Traveling Mentorship Program (ITMP) has initiated an International Mohs Fellowship Recognition Program, with 3 centers accredited to date. OBJECTIVE: To describe and compare the outcomes of Mohs micrographic surgery (MMS) at the three units. METHODS: From patient files, we extracted demographic information, as well as tumor type, location of tumor, tumor histology, stages of MMS, and outcomes. RESULTS: At the 3 units, 3,899 patients were treated with MMS over a 5-year period in the South African unit, and 1,141 cases in the Romanian unit. Over a 3-year period, 849 cases were treated in the Netherlands unit. Basal cell carcinomas (BCCs) constituted 78.9% (South African unit), 79% (Romanian unit), and 97.2% (Netherlands unit), and squamous cell carcinomas (SCCs) 17.7% (South African unit), 19% (Romanian unit), and 0.7% (Netherlands unit) of the tumors treated. The recurrence rate following MMS was low, at 0.1% (South African Unit) and 0.17% (Romanian Unit) of cases at the end of the study period, with a median follow-up time of 2 years. CONCLUSION: Mohs micrographic surgery is an effective treatment modality for removing BCC and SCC at ASDS ITMP-recognized International Mohs Fellowship units.
