Choristoma involving the floor of the mouth and the anterior tongue: a case of teratoid cyst with gastric and respiratory epithelia.

Oral dysontogenic cysts result from defective embryonic development. Among them teratoid cysts are the most unusual presentation and may be lined by gastric, intestinal, respiratory, squamous, ciliated epithelium or even pancreatic structures. Teratoid cysts containing respiratory and gastrointestinal epithelium have typically been called choristomas. This article describes a 15-year-old boy presenting a choristoma involving both the floor of the mouth and the anterior tongue and characterized by the presence of squamous epithelium with skin adnexa, gastric and respiratory epithelium.