Multiple intraoral melanoacanthomas: a case report with unusual findings

Melanoacanthoma is a rare, benign, mucocutaneous pigmented lesion characterized by colonization of acanthotic epithelium by dendritic melanocytes.(1,2) The most common intraoral sites are the buccal(3,4) and masticatory mucosa subject to chronic irritation.(1,5) The pathogenesis of oral melanoacanthoma remains uncertain, although its clinical behavior is suggestive of a reactive cause.(3,4,6,7) The clinical appearance of melanoacanthoma is nondiagnostic, and biopsy is mandatory.(2,3,5,6,8) The lesion, however, requires no treatment(5) and elimination of local irritants as well as periodic observation are the recommended interventions.(1,8) We describe a 39-year-old black patient with a recently reported palatal melanoacanthoma who developed additional lesions in other intraoral sites approximately 3 months after the initial lesion was biopsied. This article also documents the reactive and reversible nature of intraoral melanoacanthoma in a rare case of multiple lesions.