The presence of a central midline well-defined thin-walled cystic lesion resting at the floor of the mouth gives a differential of dermoid/epidermoid cyst. Dermoid cysts are more common in the head and neck region, with the presence of fat content makes it easy to differentiate from an epidermoid cyst. However, occasionally on CT basis, both can have the same appearance 1.
MRI assessment is recommended in such instances and histopathological examination of the cyst wall after excision is diagnostic. Unfortunately, both are not available on this case as the case lost follow up. Both cyst types are benign and have the same management; surgical excision. Cysts superficial to geniohyoid muscle may cause posterosuperior tongue displacement, dysphonia, dysphagia or airway obstruction.