Acral lentiginous melanoma.

Acral lentiginous melanoma represents a fourth variant of malignant melanoma in company with lentigo maligna melanoma, superficial spreading melanoma, and nodular melanoma. It is characterized by a lentiginous (radial) growth phase that evolves over months or years to a dermal (vertical) invasive stage. Clinical and pathologic features were reviewed in 35 cases of acral lentiginous melanoma of the palms and soles. This variant of melanoma probably represents the most common expression of melanoma in blacks; two thirds of the patients in our study were black. The average three-year survival rate was 11%.