Heterotopic intestinal cyst of the submandibular gland: a case study.

Heterotopic gastrointestinal cysts are rarely found in the oral cavity. Most of these cysts are lined with gastric mucosa and involve the tongue. There have been no reported heterotopic intestinal cysts of the submandibular gland that are completely lined with colonic mucosa. An 8-year-old girl presented with an enlarging swelling in the left submandibular area, and a 4-cm unilocular cyst was fully excised. The cyst was completely lined with colonic mucosa that was surrounded by smooth muscle layer, and the lining cells were positive for CDX-2, an intestinal marker, indicating a high degree of differentiation. The pathogenesis remains unclear, but it may be related to the misplacement of embryonic rests within the oral cavity during early fetal development. Although heterotopic intestinal cysts rarely occur in the submandibular gland, they should be considered in the differential diagnosis of facial swellings in the pediatric population.