Epidermoid cyst on the inferior surface of the tongue: Report of a case and review of the japanese literature.

Dermoid and epidermoid cysts are either congenital cysts caused by impaction of embryonal ectoderm or acquired cysts caused by inflammation or traumatic implantation of epithelium. In the oral region, the majority of cysts usually occur on the floor of the mouth, and occurrence in the tongue is extremely rare. We encountered a case of epidermoid cyst on the inferior surface of the tongue, and simultaneously reviewed 9 cases of dermoid and epidermoid cysts of the tongue reported in the Japanese literatures during the past 68 years. The patient was a 23-year-old male. Under the clinical diagnosis of benign tumor, the lesion was enucleated. Later, it was histopathologically diagnosed as an epidermoid cyst.