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

BACKGROUND: 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.

OBJECTIVE: We sought to review clinical and histologic features of LM and LMM and determine surgical margin necessary for complete excision.

METHODS: We conducted a retrospective study of 117 LM and LMM cases treated with a staged margin-controlled excision technique with rush paraffin-embedded sections.

RESULTS: 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.

LIMITATIONS: Retrospective and single-institution experience are limitations.

CONCLUSION: 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.