An abnormal skin growth in the middle ear behind the eardrum is called cholesteatoma. Repeated infections and/or and a tear or retraction of the eardrum can cause the skin to toughen and form an expanding sac. Cholesteatomas often devolop as cysts or pouches that shed layers of old skin, which build up inside the middle ear. Over time, the cholesteatoma can increase in size and destroy the surrounding delicate bones of the middle ear. Hearing loss, dizziness and facial muscle paralysis are rare, but can result from continued cholesteatoma growth.
What causes a cholesteatoma?
A cholesteatoma usually occurs because of poor eustachian tube function as well as infection in the middle ear. The eustachian tube conveys air from the back of the nose into the middle ear to equalize ear pressure (“clear the ears”). When the eustachian tubes work poorly, perhaps due to allergy, a cold, sinusitis or poor Eustachian tube development, the air in the middle ear is absorbed by the body, creating a partial vacuum in the ear. The vacuum pressure sucks in a pouch or sac by stretching the eardrum, especially areas weakened by previous infections. This can develop into a sac and become a cholesteatoma. A rare congenital form of cholesteatoma (one present at birth) can occur in the middle ear and elsewhere, such as in the nearby skull bones. However, the type of cholesteatoma associated with ear infections is most common.
How is cholesteatoma treated?
An examination by an otolaryngologist—head and neck surgeon can confirm the presence of a cholesteatoma. Initial treatment may consist of a careful cleaning of the ear, antibiotics and ear drops. Therapy aims to stop drainage in the ear by controlling the infection. The growth characteristics of a cholesteatoma must also be evaluated.
A large or complicated cholesteatoma usually requires surgical treatment to protect the patient from serious complications. Hearing and balance tests, x-rays of the mastoid (the skull bone next to the ear) and CAT scans (3-D x-rays) of the mastoid may be necessary. These tests are performed to determine the hearing level in the ear and the extent of destruction the cholesteatoma has caused.
Surgery is performed under general anesthesia in most cases. The primary purpose of surgery is to remove the cholesteatoma so that the ear will dry and the infection will be eliminated. Hearing preservation or restoration is the second goal of surgery. In cases of severe ear destruction, reconstruction may not be possible. Facial nerve repair or procedures to control dizziness are rarely required. Reconstruction of the middle ear is not always possible in one operation; therefore, a second operation may be performed six to 12 months later. The second operation will attempt to restore hearing and, at the same time, allow the surgeon to inspect the middle ear space and mastoid for residual cholesteatoma.
Surgery can often be done on an out-patient basis. For some patients, an overnight stay is necessary. In rare cases of serious infection, prolonged hospitalization for antibiotic treatment may be necessary. Time off from work is typically one to two weeks.
After surgery, follow-up office visits are necessary to evaluate results and to check for recurrence. In cases where an open mastoidectomy cavity has been created, office visits every few months are needed to clean out the mastoid cavity and prevent new infections. Some patients will need lifelong periodic ear examinations.
Cholesteatoma is a serious but treatable ear condition which can be diagnosed only by medical examination. Persistant earache, ear drainage, ear pressure, hearing loss, dizziness, or facial muscle weakness need to be evaluated by an otolaryngologist.
Symptoms and Dangers
Initially, the ear may drain fluid with a foul odor. As the cholesteatoma pouch or sac enlarges, it can cause a feeling of fullness or pressure in the ear, along with hearing loss. An ache behind or in the ear, especially at night, may cause significant discomfort.
Dizziness, or muscle weakness on one side of the face (the side of the infected ear) can also occur. Any or all of these symptoms are good reasons to seek medical evaluation.
An ear cholesteatoma can be dangerous and should never be ignored. Bone erosion can cause the infection to spread into the surrounding areas, including the inner ear and brain. If untreated, deafness, brain abscess, meningitis and, rarely, death can occur.