Amelanotic lentigo maligna melanoma manifesting as a dermatitislike plaque

A 72-year-old man with a previous history of an amelanotic melanoma on his left forearm had an erythematous plaque excised from his right shoulder. Although the clinical impression was a dermatitis, a biopsy specimen revealed an amelanotic lentigo maligna melanoma. To our knowledge, this is the first patient described with an amelanotic lentigo maligna melanoma as a second primary tumor to an apparent previous amelanotic melanoma, manifesting as a dermatitislike plaque.