Epidermal choristoma arising on the midline gingiva as a congenital epulis: a case report.

We report an extremely rare case of epidermal choristoma in the midline of the maxillary gingiva. A 2-month-old Japanese boy presented with a polypoid mass in the midline of the maxillary gingiva. The initial clinical diagnosis was congenital epulis. Microscopic examination revealed a granular cell layer and melanin pigmentation within the basal cell layer. Furthermore, sebaceous glands and hair follicles were observed within the connective tissue. The histological diagnosis was therefore epidermal choristoma, based on clinical microscopic observations.