Treating melanoma in situ and lentigo maligna with Mohs micrographic surgery in Australia.

BACKGROUND/OBJECTIVES: There is a paucity of Australian data on the use of Mohs micrographic surgery for treating melanoma in situ and lentigo maligna. We share an Australian centre's experience with the technique.

METHODS: A total of 62 patients with 62 lesions of melanoma in situ and lentigo maligna referred for treatment between 2015 and 2017 comprised the study group. All melanomas were excised with Mohs micrographic surgery utilising melanoma-associated antigen recognised by T-cells (MART-1) immunostaining.

RESULTS: Follow up ranged from 3 to 30 months with no reported recurrences or melanoma-related deaths. 94% (58/62) of lesions were primary melanomas and 6% were locally recurrent. 89% of lesions involved head and neck sites with 11% involving trunk or limbs. In total 55% (12/62) of lesions were cleared with 3-mm clinical margins, 68% with 6 mm, 92% with 9 mm and 100% with 12-mm. The mean clinical excision margin was 6.7 mm. All lesions with a tumour diameter greater than 2.2 cm required a 9-mm clinical margin or greater for excision. The mean clinical excision margin for recurrent tumours was 9 mm.

CONCLUSION: We provide the first Australian data on the use of Mohs micrographic surgery for melanoma.