Mohs micrographic surgery for lentigo maligna and lentigo maligna melanoma. A follow-up study.

BACKGROUND: We previously reported our experience using Mohs micrographic surgery (MMS) for 45 patients with lentigo maligna (LM) and lentigo maligna melanoma (LMM). The patients were treated between 1985 and 1992. In our initial publication, all of the patients were free of local disease and evidence of metastases at an average of 29.2 months after therapy.

OBJECTIVE: The purpose of this study was to report long-term follow-up of our previously published data.

METHODS: MMS was performed in 26 patients with LM and 19 patients with LMM using frozen sections followed by rush permanent sections. Follow-up was obtained by contacting the referring physician, examination by one of our two Mohs surgeons, or by contacting the patient or his or her family.

RESULTS: After a median follow-up of 58.0 months (214.3 patient-years), there was one recurrence. This patient was a 56-year-old woman with five prior recurrences before MMS. Six patients were decreased of other causes during the study.

CONCLUSIONS: MMS using frozen and rush permanent sections resulted in a 97% cure rate for LM and LMM. Because MMS minimizes the removal of normal tissue, and the cure rate exceeds that of conventional therapies, the authors recommend this technique for the treatment of LM and LMM.