Floor of the mouth cystic lesion

Case contributed by Dr Mostafa El-Feky


Dysphagia, difficult speech and mastication. Submandibular and floor of mouth swelling.

Patient Data

Age: 30 years
Gender: Male

CT neck

A large thin-walled cystic lesion is noted at the floor of the mouth with homogeneous fluid density (14 HU) measuring 9.2 x 5.2 x 6.0 cm in AP, ML and CC dimensions. It is stretching and displacing the genioglossus and mylohyoid muscles downwards. Inferiorly, it is reaching the hyoid bone with no erosion or related extensions.

Both submandibular glands are average in size with no stones or inflammatory changes. Moderate bilateral dilatation of intraglandular submandibular ducts bilaterally, likely due to the mass effect of the large cystic lesion of the floor of the mouth.

Case Discussion

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 for differentiation 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.

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Case information

rID: 64463
Published: 20th Sep 2019
Last edited: 20th Sep 2019
System: Head & Neck
Inclusion in quiz mode: Included
Institution: Dar El Ashaa Center

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