For a melanoma to be diagnosed, it must have neither of two morphological negative features and one or more of nine positive features. The negative features are symmetry of pattern and a single color. The positive features are blue-white veil, multiple brown dots, pseudopods, radial streaming, scar-like pigmentation, peripheral black dots or globules, five or six colors, multiple blue-gray dots, and a broadened network. This method gives a 92% sensitivity and 71% specificity for the diagnosis of melanoma.