Congenital fistula with an island of vermilion-epithelium in the paramidline of the upper lip: report of a case.

An extremely rare case of a congenital fistula with an island of vermilion-epithelium in the paramidline of the upper lip in a 17-year-old male is presented. The fistula was located in the paramidline of the philtrum dimple, and mucoid secretion from the fistula was noted. The fistula's orifice opened in the center of a well-defined, slightly dimpled, round, vermilion-like epithelium just above the vermilion border. The fistulous tract terminated in a cul-de-sac and its end was located near the alveolar process. Fistulectomy was carried out via an extra-oral approach and the epithelial defect was closed using a rotation flap. Histological examination revealed that the fistula was lined by squamous epithelium with sebaceous and mucous glands, and vermilion-like area island consisted of thin keratinized stratified squamous epithelium without skin appendages, the same as the epithelium of the lip vermilion.