Midline sublingual dermoid cyst.

The case of an 18-year-old man who presented with a large cystic mass in the floor of the mouth extending into the left submandibular triangle of the neck is reported. Histopathology of this mass, which was totally excised by a combined intra-oral and cervical approach, confirmed it to have originated in ectodermal remnants (congenital dermoid cyst) and to be actively secreting sebum. This case is reported both because dermoids at this site are rare because they may present some problems in management.