Cholesteatoma is an abnormal cyst filled with shed skin. Cholesteatoma can be acquired or congenital.
Congenital cholesteatoma arises due to skin remnants that failed to migrate from the middle ear to the outer ear (external auditory canal) during development of the fetus. As a result, a congenital cholesteatoma appears in children as an asymptomatic white mass behind the ear drum (tympanic membrane).
Acquired cholesteatoma results from untreated ear fluid (middle ear effusion), recurrent ear infections (suppurative otitis media) or an untreated hole in the ear drum. The shed dead skin in the middle of a cholesteatoma cyst acts like a foreign body and often becomes chronically infected. If untreated a cholesteatoma will grow and can be very destructive of the bone of the ear.
Cholesteatoma can cause hearing loss, dizziness and, rarely, a weakness of the muscles of the face (see Facial Nerve Disorders). The size of a cholesteatoma is usually determined with computerized tomography, a form of x-ray evaluation. Cholesteatoma is treated surgically in the majority of cases.