Lentigo maligna and lentigo maligna melanoma.

Lentigo maligna (LM) is a pigmented lesion that occurs on the sun-exposed skin, particularly the head and neck areas, of an older patient. The lesion increases in size and at some point, often many years after its onset, may become lentigo maligna melanoma (LMM). For this reason, most authors consider LM a form of melanoma in situ. Treatment includes surgical or destructive modalities; the preferred form of therapy is surgical removal. Histopathologic features include a proliferation of atypical melanocytes along the basal layer of the epidermis and adnexal structures. This article discusses the clinical, histopathologic, and epidemiologic features of LM. The prognosis and treatment of LM are reviewed. Although the lifetime risk of the development of LMM is unclear, LMM is discussed briefly.