LESSON 69

What is cholesteatoma ?

Name: What is cholesteatoma ?
Uploaded: 2026-11-04T03:15:00+03:00
Duration: 11 min 31 s
Description: In this lesson, we look at cholesteatoma: its congenital and acquired types, how it develops from a retraction pocket, ossicular erosion and conductive hearing loss. We also discuss warning signs of complications, when to refer to a physician, and audiological follow-up after mastoidectomy.

Year 1
Spring semester
Otorhinolaryngology
Outer and middle ear disorders
Duration: 11:31

In this lesson, we look at cholesteatoma: its congenital and acquired types, how it develops from a retraction pocket, ossicular erosion and conductive hearing loss. We also discuss warning signs of complications, when to refer to a physician, and audiological follow-up after mastoidectomy.

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Hello, and welcome to the AIHEAR Audiology Academy.
In this lesson, we learn about cholesteatoma, a serious middle ear disease, and why audiologists need to be careful with it.
We will cover its types, its effect on the ossicles and hearing, warning signs of complications and follow-up after surgery.
Cholesteatoma is the presence of keratin-producing stratified squamous epithelium, in other words skin, in the middle ear or mastoid.
This skin keeps producing keratin debris made of dead cells and collects it inside a sac.
The name is misleading; it is not a tumor and has no direct link to cholesterol, but it grows over time.
As it grows, the surrounding inflammation and released enzymes erode the ossicles and the nearby bone.
This is why cholesteatoma is a serious disease that can threaten hearing and nearby structures.
Medication does not cure it permanently; treatment is surgery planned by the ENT physician.
By origin, cholesteatoma is divided into congenital and acquired types.
Congenital cholesteatoma grows from epithelial remnants left in the middle ear during development and lies behind an intact eardrum.
The most common acquired form grows from a retraction pocket of an inward-pulled eardrum; this is called primary acquired.
In secondary acquired cholesteatoma, eardrum skin migrates into the middle ear, especially from the edge of a marginal perforation.
Acquired cholesteatoma is much more common than the congenital type.
The story of acquired cholesteatoma often begins with Eustachian tube dysfunction.
Long-standing negative middle ear pressure pulls the weakest part of the eardrum, the pars flaccida or flaccid part, inward.
This creates an inward dip in the eardrum, called a retraction pocket.
A shallow pocket can clear keratin, but when the pocket deepens and its opening narrows, keratin starts to collect inside.
Pars flaccida pockets extend through Prussak's space into the attic, or epitympanum.
From there, cholesteatoma can spread through the aditus ad antrum to the mastoid antrum and the mastoid air cells.
Pars flaccida retractions are commonly graded with the Tos classification, and pars tensa, or tense part, retractions with the Sade.
Congenital cholesteatoma is usually seen in childhood as a white mass behind an intact tympanic membrane.
The mass most often lies behind the anterosuperior part of the eardrum.
In the classic definition, the eardrum is intact and there is no history of perforation or ear surgery.
It often causes no symptoms and is found during routine otoscopy or hearing screening.
As it grows, it can affect the ossicles and cause a conductive loss, so a white area behind the eardrum is always reported.
The most typical sign of acquired cholesteatoma is foul-smelling, painless ear discharge that keeps returning despite treatment.
The discharge comes from infection of the keratin debris.
Hearing loss is usually conductive and increases as the disease progresses.
A feeling of fullness in the ear is also a common complaint.
In some patients, cholesteatoma causes no symptoms for a long time, which is why regular otoscopy matters.
The most important effect of cholesteatoma on hearing is erosion of the ossicular chain.
The part most often eroded is the long process of the incus and its tip that connects to the stapes.
The stapes superstructure can also erode, while the malleus is usually affected later.
When the chain is disconnected, vibration cannot reach the inner ear, and a marked conductive loss appears.
Sometimes the cholesteatoma mass itself bridges the two broken ends and carries sound to some extent.
Hearing may then be better than the extent of disease suggests, so good hearing does not mean the disease is mild.
In this example, left air conduction thresholds are between forty five and fifty five decibels HL, and the right ear is normal.
Masked bone conduction thresholds are within normal limits.
An air-bone gap of about forty decibels can fit a conductive loss with involvement of the ossicular chain.
The tympanogram may be flat with normal volume if the mass fills the middle ear, or flat with large volume if there is a perforation.
If cholesteatoma also affects the inner ear, bone conduction drops and the loss can become mixed.
So measuring masked bone conduction at every visit is the simplest way to monitor the inner ear.
If untreated, cholesteatoma can spread to nearby structures and cause serious complications.
Erosion of the bony labyrinth is called a labyrinthine fistula; it is most common in the lateral semicircular canal and can cause vertigo.
Studies report a fistula in about three to twelve percent of patients with cholesteatoma.
If the bony canal of the facial nerve erodes, facial palsy can develop.
If infection spreads to the mastoid, a painful swelling behind the ear, called mastoiditis, can appear.
Rarer but life-threatening complications include intracranial infections such as meningitis and brain abscess.
This is why every patient with suspected cholesteatoma should be evaluated by an ENT physician.
In a patient with cholesteatoma or chronic discharge, new vertigo may suggest that the labyrinth is affected.
A new drop in bone conduction compared with the previous audiogram may show that the inner ear is affected.
Facial weakness, being unable to close the eye fully or a drooping mouth corner suggests the facial nerve is affected.
Fever, severe headache, a stiff neck or a change in consciousness can be signs of an intracranial complication.
If any of these findings is present, the patient is referred to a physician without delay and the finding is written in the report.
Diagnosis and treatment of cholesteatoma belong to the physician, but the audiologist is often one of the first to encounter it.
A deep retraction pocket, a crusted attic, recurrent discharge or a white area behind the eardrum is reported to the physician.
Accurate masked bone conduction shows the state of the inner ear and the gain that can be expected from surgery.
In tests that apply pressure, the patient is watched carefully because of the possibility of a fistula.
Monitoring hearing after surgery and choosing a suitable hearing aid are also part of the audiologist's job.
In a chronically draining ear, blaming the discharge only on the hearing aid can let a cholesteatoma go unnoticed.
The goal of cholesteatoma surgery is to remove all disease, create a safe ear and, if possible, preserve hearing.
Mastoidectomy is surgery that opens and clears the mastoid air cells; it can be done while keeping the canal wall.
In some patients, the back wall of the ear canal is removed, and the mastoid and canal become a single open cavity.
Keeping the canal wall preserves natural anatomy, while an open cavity makes it easier to see any remaining disease.
For residual or recurrent disease, a second surgery or diffusion-weighted magnetic resonance imaging can be used.
Which method to choose depends on the extent of disease and is the surgeon's decision.
After surgery, air and bone conduction are measured, and bone conduction is compared with the preoperative results.
In an open cavity, the equivalent volume measured in tympanometry can be very large; this finding fits the surgery.
A wide, irregular cavity makes ear impressions difficult; feedback from the aid and moisture in the cavity can be problems.
If the cavity keeps draining, bone conduction hearing devices are also considered among the options.
Water caloric testing is not done in an open cavity; if needed, air is used, and the response may be stronger than expected.
The cavity is cleaned regularly under the physician's care; the audiologist checks it with otoscopy before every measurement.
A tip from practice: watch the patient when doing tympanometry in an ear with chronic discharge or cholesteatoma.
If dizziness, nausea or eye movements appear during the pressure change, stop the test right away.
This can be a sign of a labyrinthine fistula; this pressure-induced response is also the basis of the fistula test.
Write the finding in your report and inform the physician; do not repeat pressure-based tests in that ear.
Cholesteatoma is a buildup of keratin-producing skin and keratin debris in the middle ear or mastoid.
Acquired cholesteatoma usually grows from a pars flaccida retraction pocket; the congenital type lies behind an intact eardrum.
Ossicular erosion, especially of the long process of the incus, leads to a conductive loss.
Signs such as vertigo, a drop in bone conduction and facial palsy suggest a complication and are referred to a physician.
Test yourself: Which part of the ossicles erodes most often in cholesteatoma?
The correct answer is B: the long process of the incus.
The long process of the incus, which connects to the stapes, is thin with a poor blood supply; when it erodes, the chain breaks.
In the next lesson, we will look at otosclerosis, in which the stapes loses its mobility behind an intact eardrum, and the Carhart notch.
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Prerequisites

LESSON 68 Eardrum perforation