Congenital teratoid cyst of the floor of the mouth

Abstract

Erich’ first used the term “dysontogenetic,” meaning disturbance in embryologic development, in referring to the origin of dermoid cysts of the floor of the mouth. Several mechanisms have since been reported in the literature concerning the embryologic basis for their occurrence. Eppley3 listed four mechanisms. These included: 1) submergence of ectodermal cells that were pinched off at the time of closure of the anterior neuropore; 2) entrapment of ectodermal rests during closure of the first and second branchial arches at the midline position; 3) remnants of the anterior tongue precursor, the tuberculum impar; and 4) misplacement of the adjacent embryologic tissues (i.e., foregut). The term dermoid cyst appears frequently in the literature and Meyer4 suggested retaining its use for all types of developmental cysts of the mouth floor. In a review of the literature, Eppley3 states that two types of congenital floor of the mouth cysts exist; the dermoid and heterotopic gastrointestinal cysts. Gorlin,’ in a review of the literature, described 13 cases of the choriostomatic cyst of gastric or intestinal epithelium. He theorized that mixtures of endodermal and ectodermal tissue could give rise to cysts containing both germ layers. Dermoid cysts of the floor of the mouth are rare but well-documented in the literature. Erich and New6 reported 1495 dermoid cysts. In this population, 103 (6.9%) were located in the head and neck. Twenty-five percent of the head and neck dermoids were present in the oral