Malignant melanoma. The antecedent lesion--junction nevus?
D002471:Cell Transformation, Neoplastic / Q000503:physiopathology; D006801:Humans; D008545:Melanoma / Q000503:physiopathology*; D009508:Nevus, Pigmented / Q000503:physiopathology*; D012878:Skin Neoplasms / Q000503:physiopathology*