Dermoid cysts are relatively thick-walled cysts containing hair follicles and glandular tissue, principally located in the posterior fossa. They may also arise in the cerebellopontine angle.
They may be in contact with the skin surface through a bony defect and act as a source for infection and consequent meningitis. They may also cause multiple cranial nerve palsies.
They appear as low density lesions on CT similar to epidermoid cysts except that they are often calcified.
Removal is often difficult because of adherence to adjacent structures but symptoms may be relieved by operative evacuation.
Last reviewed 01/2018