Oral melanoacanthoma: a case report and review of the literature

INTRODUCTION Oral melanoacanthoma is a rare, benign pigmented lesion characterized clinically by the sudden appearance and rapid growth of a macular brown-black lesion and histologically by acanthosis of the superficial epithelium and proliferation of dendritic melanocytes. CASE PRESENTATION We present a case report of oral melanoacanthoma in a 24-year-old Asian Indian man. He presented with an intra-oral brown macular lesion on the left buccal mucosa with a duration of one and a half months. Microscopic examination revealed acanthosis of stratified squamous surface epithelium and dendritic melanocytes diffusely distributed in the epithelium; the Masson-Fontana silver impregnation technique was used to demonstrate the dendritic melanocytes. Based on the history, clinical features and histological presentation, the lesion was diagnosed as melanoacanthoma. CONCLUSION This is the first reported instance of oral melanoacanthoma in the Indian sub-continent. This report details the course of the lesion from diagnosis to its resolution. Melanoacanthoma must be differentiated from other intra-oral pigmented lesions and biopsy may be required to rule out melanoma.