Epidermoid Cyst Arising on the Body of the Tongue: Case Report and Literature Review.

BACKGROUND: Epidermoid cysts of the body of the tongue are rare. Only 12 cases of such lesions have been reported in the English literature.

CASE: A 14-year-old boy had a 7×5-mm-sized cystic lesion with a yellowish-white surface on the ventral aspect of his tongue. The cystic wall was composed of squamous epithelium containing keratinous material. No skin appendages were attached to the wall. These findings were consistent with a diagnosis of an epidermoid cyst.

LITERATURE REVIEW: For the thirteen cases, including ours, the average age was 18.0 years. The highest incidence was found in the first decade of life. Eight of the patients were male and five were female. The size varied from several millimeters to several centimeters. There may be a left side predilection of the occurrence. There is no evidence for malignant transformation of epidermoid cysts of the tongue, though two cases were reported as carcinoma arising from an epidermoid or dermoid cyst of another oral area.

DISCUSSION: Epidermoid cysts of the body of the tongue are congenital or acquired. The congenital type can arise due to a failure of surface ectoderm separation or invagination of the surface ectoderm along the embryologic fusion sites. The acquired type is caused by trauma, with implanting of an epithelial element into the deeper tissue. In the present case, it was difficult to determine whether the pathogenesis was congenital or acquired because there are no clinical or histopathological differences between the two types.