A cholesteatoma is a smelly, white mass of skin scales and debris in the middle ear. It can cause hearing loss and extensive destruction of bones. The surgery done to cure cholesteatoma is called mastoidectomy.
The majority of cholesteatomas, especially in adults, are acquired. They are a result of severe infections from perforations of the eardrum or are the result of chronic middle ear problems.
Also, the eardrum can be progressively pulled down and retracted into the middle ear space. The skin of the ear drum then grows inside the middle ear and mastoid to form a cholesteatoma. Less commonly, cholesteatomas may form congenitally
Cholesteatomas, when small, can often be removed without separating the bones of hearing. Larger cholesteatomas may require extensive surgery. Large cholesteatomas can be very deep in the inner ear. These usually present extensive hearing loss and facial weakness on the side of the cholesteatoma.
As acquired or congenital cholesteatomas increase in size, they can also affect the nerve that moves the face, the facial nerve. This nerve extends from the brain to the face by going through the inner ear, the middle ear, exiting near the forward tip of the mastoid bone, rising up to the front of the ear, and finally branching into the upper and lower face. Infected cholesteatomas may erode the bone covering this nerve. Pressure or irritation by the cholesteatoma on the facial nerve may then result in facial weakness or actual paralysis of the face on the side of the involved ear. In this case ear surgery may be necessary on an emergency basis to prevent permanent facial paralysis.
In more extensive cholesteatomas, the tumour may have eroded through the bony wall which separates the middle ear from the mastoid. This may require a more radical operation, removing the wall separating the middle ear from the mastoid.
In congenital cholesteatomas, the eardrum is intact and there is no infection present, so the surgery can be performed more quickly.
Hearing reconstruction is often delayed because it is necessary to rebuild the bones of hearing at a future date.
With an intact canal wall, rebuilding the bones of hearing is delayed for a year after the primary operation for cholesteatoma. The eardrum is opened at the second operation and the bones of hearing are then reconstructed.
Most cholesteatomas require that an incision is made behind the ear to expose the disease adequately. The cholesteatoma is completely removed microscopically
Even with the careful microscopic surgical removal of cholesteatoma, 10% to 20% of cholesteatomas can recur. Thus, careful follow-up visits must be planned, in order to identify regrowth early on.