Three cases of malignant melanoma arising on burn scars.

It is well known that up to 2% of chronic burn scar lesions can transform into malignant tumors. Most of them are squamous cell carcinoma (SCC) and, more occasionally, basal cell carcinoma (BCC). The incidence of malignant melanoma (MM) is extremely low. To the best of our knowledge, there are only 23 such cases reported in the literature. We report here three cases of MM arising on burn scars and analyze the 23 cases reported previously. Case 1: a 74-year-old Japanese man sustained a burn injury on about 54% of his whole body surface when he was accidentally bathed in boiling oil at the age of 37 years old. Some small tumors developed on the burn scar on his right lumbar region. A wide excision of the tumor was performed. Case 2: a 51-year-old Japanese woman was injured on her right forearm and face by deep burns from a flame when she was 7 months old. She presented with a rapidly growing, painless black nodule on the dark skin lesion on her right forearm. She was treated with a wide excision followed by a full-thickness skin graft. Intravenous administration of one unit of OK-432 every week has been continued. Case 3: a 73-year-old Japanese woman was burned on her left leg and hand from a flame when she was 6 years old. A nodular lesion appeared within the ulcer two months previously and it was growing rapidly. This lesion was ulcerated on the top of its central area and was slightly reddish without any pigmentation. The patient was treated with a wide excision and a split-thickness skin graft. The 5-year survival rate of MM in an old burn scar is 53.6%. It is suggested that the prognosis of burn scar carcinoma is not worse than that of non-burn scar carcinoma.