Timothy C. Hain, MD
Page last modified: July 7, 2016
Cholesteatomas are tumor like growths in the middle ear (see above). They are generally formed from the skin cells on the outside of the eardrum, that have become folded into the middle ear as a result of an ear infection with a perforation of the ear drum. Some are also congenital due to pockets of tissue located in the middle ear.
A cholesteatoma may form a cyst within the middle ear consisting of squamous epithelium (skin), often containing cholesterol crystals.
Presenting symptoms commonly include hearing loss on one side (of the conductive type), ear pain, and drainage. Dizziness is an occasional symptom.
Damage to the middle and inner ear from a cholesteatoma is due to erosion and expansion of the cholesteatoma. This generally occurs gradually over years. Hearing is usually lost first as the cholesteatoma destroys the ossicles of the middle ear and fills the middle ear.
Dizziness may occur if the cholesteatoma erodes into the inner ear -- for example, a cholesteatoma may break into the horizontal semicircular canal, causing an "otic capsule fistula".
Most individuals with cholesteatoma will have a large number of abnormal ear tests.
- Audiograms -- usually will show a conductive hearing loss
- Tympanograms -- usually will show a perforation of the ear drum.
- VEMP test -- usually absent on the side of the cholesteatoma.
- MRI scan -- soft tissue is seen in the middle ear. This is not specific for cholesteatoma, but it is sensitive. T1 weighted 3T MRI using DWI (and contrast) is currently thought to be the most sensitive technique. (Steens, 2016).
- CT-scan of the temporal bone -- bony erosion may be seen of the temporal bone accompanying the soft tissue in the middle ear. The CT is the most specific test, but entails considerable radiation. When the diagnosis of Cholesteatoma is already certain (perhaps one is looking for recurrence), DWI MRI may be the better choice.
The coronal CT scan above was done on a patient after a mastoidectomay (canal wall down), and shows recurrent cholesteatoma.
At the bedside, there should be an abnormal ear drum and a conductive hearing loss (which can be detected with tuning fork tests).
Erosion of the cholesteatoma into the inner ear can be recognized by dizziness induced by pressure, provoked by the "Valsalva" test , or dizziness induced by sound provoked by the "Tullio" test. These are very specific findings.
Surgery is the main treatment for cholesteatoma. An attempt is made to excise the inflammatory mass.
There are two general types of surgery - -
- canal wall up (CWU)
- canal wall down (CWD)
In both of these surgeries the goal is to removed the "matrix" of inflammatory cells as well as to facilitate ongoing monitoring for recurrence. In the CWD procedure the mastoid is opened, which can leave behind a large opening in the external ear canal, requiring periodic cleaning.
It is generally thought that surgeries that provide greater exposure - - CWU, have less recurrence. In CWD surgeries, a recent study found residual cholesteatoma in about 20% (Haginomori et al, 2008).
Hearing usually improves by about 20db after surgery for cholesteatoma (Stankovic, 2008) Hearing is generally stable in persons after surgery, unless there is recurrence. In children, cholesteatoma has no long term effect on school performance for the majority who complete lower secondary school (Djurhuus et al, 2016).