Two cases of melanoacanthoma occurring on oral mucous membranes are presented. Melanoacanthoma is considered to be a benign mixed tumor of keratinoacytes admixed with pigment-laden dendritic melanocytes. All intraoral melanoacanthomas reported thus far have been pigmented lesions of the buccal mucosa and have occurred in young to middle-aged black females. These tumors may grow rapidly and therefore they often mimic the radial growth phase of an intraoral melanoma. Because melanocanthomas have no distinguishing clinical features, biopsy is mandatory.
