RESUMO
Lentigo maligna(LM) is a pigmented lesion that occurs on the sun-exposed skin of an older patients and may become lentigo maligna melanoma(LMM). Currently the percentage of LM type melanoma appears to be increasing, and this rise has been attributed to increasing UV radiation exposure. In addition to UV radiation, estrogen and progesterone, and nonpermanent hair dyes have been proposed as risk factors. A case is a 66-year-old female with a 3 years history of pigmented patch. She had a gradually enlarging irregular bordered brown to black mottled patch on the right temple area. Histologic examination revealed atypical melanocytes along the basal layer of atrophic epidermis, arranged in solitary units and small nests. Perilesional skin showed many scattered melanophages and regressing nevus cell nests which suggested preexisting nevus underwent regressive change. On the basis of clinicopathologic examination we diagnosed this case as lenigo maligna arising from nevocytic nevus and then we removed the lesion by wide surgical excision and could not find any recurrence until now.