There are two types of cholesteatoma, congenital cholesteatoma (present at birth) where some skins cells grow in the wrong place behind the eardrum and develop into a cholesteatoma over time and acquired cholesteatoma (develops later in life).
A cholesteatoma is an accumulation of dead skin that occurs and grows in the middle ear behind the tympanic membrane (eardrum). A cholesteatoma usually occurs because of eustachian tube dysfunction and or chronic (longstanding) infection of the middle ear. (Otitis media). When working correctly the eustachian tube (the tube connecting the middle ear to the back of the throat), aerates the middle ear and equalises pressure between the outer and middle ear.If this function stops working, the air in the middle ear is absorbed, resulting in a buildup of negative pressure. This negative pressure may cause the tympanic membrane to retract and if there are any areas of weakness (usually from previous infections) a pocket or sac may be formed by the weakened area being sucked inwards. In this pocket or sac skin cells get trapped, being unable to disperse and continue to multiply, effectively growing in the middle ear cavity.
A cholesteatoma can increase in size over time and may destroy the surrounding ossicular bones (malleus, incus and stapes) of the middle ear, affect the facial nerve, in extreme cases it can impair the cochlea (inner ear) causing deafness and the infection can even reach the brain. Hearing loss, dizziness, and facial muscle paralysis are rare but can result from cholesteatomas.
A foul smelling discharge may be one of the first symptoms noticed and as the cholesteatoma enlarges, it can cause a feeling of fullness in the ear, along with hearing loss, tinnitus and earache, usually behind the ear. It can also cause vertigo, dizziness and muscle weakness on the infected side of the face. (facial palsy).
After assessment, initial treatment may consist of a careful cleaning of the ear and antibiotics to clear up any infection but some cholesteatomas will require surgical intervention to remove the cholesteatoma and any infection but also to preserve hearing ability.
Treatment: Tympanomastoidectomy: This is removal of the tympanic membrane (ear drum) and all or part of the mastoid bone of the skull, (this is the rounded bone you can feel behind your ears) depending on the size and spread of the cholesteatoma. It is a common procedure but the remaining cavity left in the ear will require regular assessment and cleaning (removal of wax).Tympanoplasty: This is a less invasive technique usually with a better cosmetic appearance post surgery. However, it is associated with a higher risk of recurrence of cholesteatoma. Avoiding surgery the cholesteatoma may be treated with the aid of 'aural toilet'. This involves washing out the ear canal and sucking out any debris. This however has to be done on a regular basis and does not prevent growth of the cholesteatoma.