Abstract

A 65 years old woman with malignant melanoma in situ, measuring 4mm in diameter, was examined. She presented with slowly growing brown, flat lesion on the left tigh of 1 year duration. The edge of the lesion was irregular, and its color was variegated dark brown in center and lower end to brown in periphery. Histopathological findings showed the lesion to be asymmetrical with unsharp lateral margins and mild inflammatory infiltrates in the upper dermis. Rete ridges were slightly elongated and there were tumor cells with atypical nuclei nested and scattered in the lowere epidermis. The tumor cells reacted strongly to monoclonal anti-HMB-45 antibody.