Congenital oral gastrointestinal cyst: an immunohistochemical analysis.

Cystic lesions of the oral cavity are quite common. Mostly their morphology is that of simple cystic lesions lined by squamous epithelium. Rarely the epithelium may be of another type, e.g. that of gastrointestinal tract. In the English literature in English about 30 cases of oral cysts with gastrointestinal epithelium lining have been reported. This developmental lesion is very rare and is found more frequently in young males. The majority of lesions were reported to occur in the ventral surface of the anterior tongue and extend to the floor of the mouth. Heterotopic gastrointestinal epithelium has been more commonly described in the duodenum, gallbladder, jejunum, Meckel's diverticulum, ileum, appendix, colon and rectum. We report an oral heterotopic gastrointestinal cyst in a child. A healthy 2-month-old boy had an asymptomatic swelling in the sublingual area that had been present since birth. Under general anesthesia, the patient underwent conservative excision of the cyst. Gross examination of the excised tissue showed a monolocular cystic lesion in the bottom of the oral cavity. Microscopically, the cystic lining mostly resembled intestinal mucosa; in some places, stratified squamous and columnar epithelium was also present. The pathogenesis of this lesion remains uncertain. Several theories have been postulated; the most commonly held suggests that these cysts may be derived from misplacement of embryonic rests.