| Abstract: | A case of a 51 year old man with a plantar malignant melanoma is reported. The tumor had clinical and histologic features of lentigo maligna melanoma, but its biologic activity was that of a more potently malignant tumor. Electron microscopic observation reveales features similar to that of lentigo maligna melanoma, but not inconsistent with that of superficial spreading melanoma. A consideration of our case and of previous reports suggests that there is a relationship between the biologic potency and the site of involvement of lentigo maligna melanoma and that such lesions on relatively non-pigmented areas such as the palms, soles, mucous membranes, and nail beds should be treated as having a highly malignant potential. |
