Cholesteatoma
is the name given to skin lined tumors
of the middle ear and mastoid. Roughly
speaking, there are two kinds of
cholesteatomas: congenital and
acquired. Congenital cholesteatomas are
usually found in children and arise from
small islands of skin trapped in the
middle ear during development. This
form of cholesteatoma is rare, but
removal of these tumors follows the same
principles used for acquired
cholesteatomas.
Acquired
cholesteatomas are due to either a hole
in the eardrum or a retracted eardrum
(resulting from problems with the
function of the Eustachian tube). These
tumors arise from the skin that covers
the eardrum. Normally, the skin of the
eardrum migrates from the center of the
eardrum out to the ear canal. The ear
canal skin moves from the inner part of
the canal towards the outer ear canal.
This movement produces the self-cleaning
mechanism of the ear canal.
In patients who
have either holes in the eardrum
(tympanic membrane perforation) or
Eustachian tube dysfunction, the skin of
the eardrum can either migrate into the
middle ear space or can accumulate
within pockets of a retracted eardrum.
The skin cells then accumulate and grow
layer upon layer like an onion to form a
cholesteatoma.
As
cholesteatomas grow, they can destroy
the ossicles (malleus, incus and
stapes), the inner ear (horizontal
semicircular canal) or the facial
nerve. These tumors can present with
symptoms such as pain or pressure in the
ear, hearing loss, dizziness, ringing
sound (tinnitus), or drainage.
A close
inspection of the ear canal and eardrum
allows your physician to diagnose this
condition. An audiogram is an essential
part of the evaluation. Occasionally, a
CT scan is required to determine the
extent of the cholesteatoma or its
involvement of the inner ear or facial
nerve.
The main
treatment for cholesteatoma is surgical
removal of the tumor. The primary goal
of such an operation is complete removal
of the cholesteatoma. In some patients
the conductive hearing mechanism can be
repaired at the same operation or at a
second stage procedure.
Many patients
have an infected cholesteatoma when they
come to the physician. Antibiotic
drops, and sometimes oral antibiotics,
are necessary to treat the infection
prior to surgery.
Since these tumors
involve the middle ear and mastoid,
tympanoplasty and mastoidectomy are
necessary to remove them. Please see
the sections on
tympanoplasty
and
mastoidectomy.
