Hourglass-shaped sublingual dermoid cyst: MRI features.

Dermoid cysts located in the floor of the mouth are classified as submental or sublingual based on their location with respect to the mylohyoid muscle. The lesion was located in the midline, involved the genioglossus and geniohyoid muscles, and extended down to the area superior to the mylohyoid muscle. An hourglass-shaped cyst of the floor of mouth was seen. Such magnetic resonance imaging findings appear to be characteristic of an extended sublingual dermoid cyst.