Cholesteatoma is a benign growth caused by the build-up of skin cells and protein from the ear canal behind the eardrum.
The outer ear is lined with a layer of skin that casts off dead cells containing keratin, a protein. This discharge, a component of earwax, occurs normally and is removed when the ears are routinely cleaned.
If, however, a bit of this skin penetrates the eardrum — which can occur for a number of reasons — the keratin that continues to be given off by the skin becomes trapped in the middle ear and builds-up over time, resulting in a cholesteatoma. If left untreated, the growth can erode the ossicles (the tiny hearing bones of the middle ear) and cause a conductive hearing loss. It can further fill the mastoid and destroy structures of the inner ear, causing permanent, sensorineural hearing loss. Unchecked, this tumor-like growth has the potential to cause facial paralysis, hydrocephalus, meningitis, or a brain abscess.
Although some patients have very mild or no symptoms of cholesteatoma, the most common sign of the condition is frequent ear infections, possibly with a foul smelling discharge from the ear. Coincident loss of hearing is often present.
The diagnosis of cholesteatoma is primarily made by microscopic examination of the ear during an office visit. An audiogram, or hearing test, is important to determine if the hearing has been damaged and a CT scan of the temporal bone (the bone containing the inner part of the ear) is required to determine the extent to which the cholesteatoma has spread.
The primary goal of treatment is to control the infection and bone destruction caused by a growing cholesteatoma; restoring the ability to hear is a secondary objective. If the cholesteatoma is small and hearing loss remains at acceptable levels, then microscopic cleaning may be performed during an office visit to clean the keratin out of the ear.
For a more advanced cholesteatoma, a mastoidectomy may be performed. Depending on the unique circumstances, a patient might also receive a tympanoplasty and ossicular (hearing) reconstruction. Mastoidectomy is a surgical procedure designed to remove cholesteatoma and infections from within the mastoid bone, which protects the structures of the middle and inner ear. Tympanoplasty is the surgical reconstruction of the eardrum and hearing apparatus. Ossicular reconstruction may be necessary if the infection has eroded the bones of the middle ear. The damaged bones are replaced by bone or a prosthesis, which restores the proper function of the middle ear.
As cholesteatomas can recur, close post-surgical follow-up is very important. Additional surgery is sometimes required to achieve complete removal.