A cholesteatoma is a non-cancerous, abnormal skin growth, or cyst, that can develop behind the eardrum. Although it can rarely be the result of a birth defect (congenital cholesteatoma), it's most commonly caused by repeated middle-ear infections and poor eustachian tube function.
The eustachian tube travels from the middle ear to the nasopharynx (the area at the back of the nasal cavity) to allow for fluid drainage and pressure equalization. If the tube gets clogged due to infection or allergies, a vacuum can form and cause the the tympanic membrane (eardrum) to bulge and form a sac. Skin cells can collect in this sac and eventually form a cholesteatoma. This is also known as primary acquired cholesteatoma.
A cholesteatoma can also form behind a perforation of the tympanic membrane due to past infections or trauma. The perforation can allow skin cells to pass into the middle ear and form a cyst. This is known as secondary acquired cholesteatoma.
Left untreated, a cholesteatoma may continue to grow and damage the fragile bones of the inner ear due to the erosive enzymes it produces. These enzymes can also cause infection to spread to surrounding areas. Other serious issues could arise if left untreated for a sustained period. These may include:
- Inner ear infection
- Paralysis of the facial muscles
- Brain abscess
While the above issues are rare, it’s important to contact your ENT specialist if you experience any signs or symptoms of a cholesteatoma.
Cholesteatoma Signs and Symptoms
Although cholesteatomas are sometimes asymptomatic, if undetected and left unchecked they could present with the following symptoms:
- Discharge (often foul-smelling) from one ear
- Pain behind the ear
- Tinnitus ( a ringing or “whooshing” sound in the ear)
The discharge is caused by infection that generally develops as the cholesteatoma grows. The cyst can also cause pain and ringing in the ear as it continues to grow from the tympanic membrane and further into the middle ear.
In extreme cases, the enzymes that the cholesteatoma releases can erode the bones in the surrounding area. This can damage the tiny, fragile bones in the middle ear (ossicles) responsible for transmitting vibrations from the tympanic membrane to the cochlea where the vibrations are processed and sent to the auditory nerve. Damage to the ossicles could cause hearing loss.
The enzymes can also erode the thin wall of bone surrounding the cochlea and cause infection in the inner ear. Infection in this area could cause vertigo or dizziness since the cochlea is also responsible for balance.
Diagnosis of Cholesteatoma
During the initial exam, your health care provider may suspect an ear infection based on the initial symptoms. The symptoms may not be alleviated with antibiotic therapy. Upon further examination, your provider may notice a crust in the upper part of the middle ear (the attic). There may or may not be a perforation of the tympanic membrane.
A hearing test, or audiogram, is generally performed to determine the level of hearing loss (if any). A balance test may also be performed to detect any balance issues caused by the cyst.
If it’s suspected that the cholesteatoma has damaged the surrounding bone, a CT (computed tomography) scan may be ordered to determine the extent of the damage. An MRI (magnetic resonance imaging) might also be ordered to determine if there are any complications (e.g. an abscess) in the intracranial space should damage to the bone leading to the cranium be evident.
Treatment of Cholesteatoma
Antibiotics may treat the underlying infection brought on by a cholesteatoma but symptoms will most likely recur if the cyst itself is not removed. In some rare cases, if the cyst is small enough, it may be treated without surgery with frequent, professional cleaning and antibiotic drops. However, surgery is usually required to remove the cyst.
The procedure, a combination of removing the diseased bone tissue and repairing the tympanic membrane, is known as a tympanomastoidectomy. The middle ear is accessed by making an incision behind the ear and pulling the ear forward to expose the bone beneath. The infected bone tissue, as well as the the cholesteatoma, is removed during this phase. The tympanic membrane is then repaired with muscle lining from behind the that was saved during the initial incisions to expose the bone behind the ear.
Care is also taken to protect the ossicles during the procedures but they may need to be removed if they are too damaged. They can be repaired or replaced with prosthetics or real bone in a future surgery if necessary.
Cholesteatoma surgery is usually done under general anesthesia. It’s occasionally performed under sedation and a local anesthetic. Surgery usually takes two to three hours and patients can generally go home the same day. Patients should expect to spend one to two weeks off work or school to recover fully.
Rigorous activity should also be avoided during this time frame. Any activities that cause pressure in your ears should also be avoided. These activities include but are not limited to:
- Contact sports
- Heavy lifting
- Strenuous exercise
Where to Get Help for Cholesteatoma
If you’re experiencing any or all of the symptoms above and suspect you may have a cholesteatoma, call Houston ENT & Allergy at 281-649-7000 to schedule a visit or click here to “find an ENT doctor near me.”