Giant Dermoid Cyst in the Floor of the Mouth Totally Excised by an Intra-Oral Approach.

Dermoid cyst is commonly considered a rare finding in the floor of the mouth. We report a 20-year-old man who presented with a large cystic mass in the floor of the mouth extending into the submandibular region. The mass, which was totally excised by an intra-oral approach, was lined by squamous epithelium containing sweat glands, sebaceous glands and hair follicles and diagnosed as a dermoid cyst. In our case, the classification of Bergman-Hagisaki from relationships to the mylohyoid muscle was of little importance in determining the presentation of the cyst or the surgical approach. The cyst lining is generally so thick that it is relative easy to excise the cyst totally. Therefore, the intra-oral approach should be attempted first, even if the cyst is large. When the removal of cyst by an intra-oral approach is difficult, extra-oral approach must be combined.