CHOLESTEATOMA

What is a cholesteatoma?
Cholesteatoma is a skin growth in an abnormal location. It is most commonly seen in the middle ear and mastoid. Cholesteatoma is most often the result of chronic infection. This process results in ingrowth of the skin of the eardrum and ear canal into the middle ear and mastoid. Over time, cholesteatomas tend to grow and destroy surrounding structures. While cholesteatomas are not tumors, they share similar characteristics. They can destroy bone, be a seed for infection and may recur. Initially, cholesteatoma will destroy the middle ear hearing bones. If allowed to grow however, it may invade the inner ear, resulting in hearing loss, dizziness, and facial paralysis. If left uncontrolled, cholesteatoma may even invade the skull, increasing the risk of infection in this area, leading to meningitis and brain abscess.


How does cholesteatoma occur?
Cholesteatoma typically occurs as a result of poor eustachian tube function. The eustachian tube is the structure that passes from the middle ear to the back of nose, which allows one to equalize ear pressure ("pop the ear"). In some individuals, this structure does not function well. This will result in a vacuum effect in the middle ear. This then sucks in the skin of the ear canal and eardrum, escpecially if it has been weakened by previous middle ear infections. As the skin begins to accumulate, a cystic structure develops, forming the cholesteatoma. A rare form of cholesteatoma may be congenital, which may occur anywhere in the middle ear and mastoid.


What are the symptoms of cholesteatoma?
Infection will develop as the cholesteatoma grows. The infection will most often be characterized by drainage through the ear canal. As the cholesteatoma enlarges, hearing will decrease. If left untreated, symptoms of dizziness and pain may be seen. In advanced cases, weakness of the facial muscles on the involved side may occur.


What is the treatment for cholesteatoma?
Cholesteatoma is usually diagnosed by examination of the ear. A hearing test (audiogram) is usually performed. In some cases, a C-T scan may be obtained to determine the extent to the cholesteatoma.

Initial treatment of cholesteatoma is directed at controlling any infection. This involves cleaning the ear, antibiotic ear drops and at times, oral antibiotics as well. The goal of this therapy is to decrease or stop the drainage in preparation for definitive treatment. Definitive treatment of cholesteatoma requires surgery. The procedure most often performed is a tympanomastoidectomy. This is done under general anesthesia. The purpose of the operation is to remove the cholesteatoma and rebuild the eardrum to prevent the possibility of recurrence. The procedure is performed through an incision in the crease behind the ear. The operation is always done with the operating microscope. During surgery, the mastoid is opened and the eardrum elevated. Once all disease is removed, the eardrum and any bony defects of the ear canal are rebuilt. The eardrum is reconstructed with a graft, most often obtained from the lining of muscle (fascia) behind the ear. If there is a defect of the ear canal adjacent to the eardrum, it may be reconstructed with cartilage.

Most often, the cholesteatoma will result in destruction of one or more of the three middle ear hearing bones. While the hearing bones can be rebuilt, it is typically performed at a second stage. This is staged for two reasons. First, cholesteatoma has a recurrence rate of about 15%. A second procedure performed through the ear canal 6 to 12 months after the initial procedure will allow the surgeon to remove any recurrent disease. Secondly, at the time of the initial procedure, the ear is infected. The reconstruction of the middle hearing bones is performed with a prosthesis (artificial bone). Introduction of a prosthesis into an infected middle ear at the time of the initial procedure may result on rejection of any reconstructive materials. Therefore, the reconstruction of the middle ear hearing bones is performed at the second stage, when the middle ear is dry and noninfected.

If the cholesteatoma is extensive, the tympanomastoidectomy may require removal of the ear canal. This will allow for the mastoid to be visualized through the opening of the ear and minmize the possibility of recurrence. This will result however, in an open mastoid cavity, requiring periodic care by the surgeon.

A tympanomastoidectomy is usually a 1 - 2 hour procedure. Patients may discharged later that day or the next morning. The second stage procedure is usually performed on an outpatient basis. The recovery from the surgery is about one week. Since cholesteatoma may recur, it is important for the patient to follow up in the office on a regular basis.