Mucinous naevocellular naevi.

We report 4 cases of a naevocellular naevus variant containing abundant amounts of mucinous matrix. The mucinous matrix was Alcian blue (pH 2.5) and Halle's colloidal iron positive and mucicarmine and PAS negative. When the blocks of tumours were cut down, regions typical of common intradermal naevi were found in all 4 cases. The differential diagnosis with mucinous carcinoma of the skin and myxoid malignant melanoma is discussed.