Staged excision for lentigo maligna and lentigo maligna melanoma: A retrospective analysis of 117 cases.

Abstract

Complete surgical excision for lentigo maligna (LM) and LM melanoma (LMM) in the head and neck region may be challenging because of potential significant subclinical extension. We sought to review clinical and histologic features of LM and LMM and determine surgical margin necessary for complete excision. We conducted a retrospective study of 117 LM and LMM cases treated with a staged margin-controlled excision technique with rush paraffin-embedded sections. The mean total surgical margin required for excision of LM was 7.1 mm and was 10.3 mm for LMM. Of the tumors diagnosed as LM on initial biopsy specimen, 16% were found to have unsuspected invasion. Total surgical margin was associated with initial clinical lesion diameter. Retrospective and single-institution experience are limitations. This study corroborates that the standard excision margins for LM and LMM are often inadequate and occult invasive melanoma occurs in LM. An excision technique with permanent sections using a team of dermatopathology and surgery that carefully examines the central tumor and the surgical margins is reliable for the treatment of LM and LMM.