Vitiliginous achromia with malignant melanoma. Tyrosinase activity and ultrastructural study of achromic and normal skin.

Vitiliginous achromia with malignant melanoma shows some discrepancies with vitiligo. In both achromic and normal skin, four bands A, B, C, D of tyrosinase activity are observed; in vitiligo only bands A and B appear. Ultrastructural findings in achromic skin are similar in both conditions. But in achromia with malignant melanoma, melanocyte abnormalities are also present in normal skin and the role of immunological factors is discussed.