Cholesteatoma - Diagnosis

How is a cholesteatoma diagnosed?

The GP or ear specialist (ENT doctor) may suspect cholesteatoma based on the typical symptoms. When the ear is examined with a torch (an otoscope), the cholesteatoma may be seen. Often there is a hole (perforation) in the eardrum (the tympanic membrane) too.

Because the symptoms come on slowly and mimic common ear infections, the diagnosis is often delayed.

  • It is very difficult for a GP to see a cholesteatoma because usually it causes a lot of pus in the ear which blocks the view to the eardrum.
  • For this reason the diagnosis is made by an ear specialist at a hospital.
  • The ear specialist will use a tiny suction tube to suck away the discharge and look at the eardrum in detail with a microscope that magnifies the view.
  • By looking in detail, close up, at the eardrum, a specialist can see the cholesteatoma pushing through the eardrum.
  • To then see how far it has spread inside the ear, a specialist scan is needed: this is usually a CT scan (which takes about 30 seconds) or an MRI scan (which can take about half an hour).

What does a cholesteatoma look like?

In the image below, the white arrow on the left shows a cholesteatoma. The white tube underneath is a grommet that was put in to try to help the middle ear. The picture on the right shows what the surgeon has removed: a pale, greasy mass of cholesteatoma. It is just a few millimetres in size.

Open access picture of cholesteatoma from

Do I need any further tests?

Hearing tests (audiometry) may show deafness or hearing loss and are usually performed in a hospital clinic. Samples (swabs) of the ear discharge may also be taken. The discharge often contains a germ (bacterium) called Pseudomonas which is responsible for the smell. A CT scan might be needed to see the extent of the damage caused by the cholesteatoma, and to plan further treatment.

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Dr Oliver Starr
Peer Reviewer:
Dr Helen Huins
Document ID:
13267 (v4)
Last Checked:
09 May 2017
Next Review:
29 June 2020

Disclaimer: This article is for information only and should not be used for the diagnosis or treatment of medical conditions. Patient Platform Limited has used all reasonable care in compiling the information but make no warranty as to its accuracy. Consult a doctor or other health care professional for diagnosis and treatment of medical conditions. For details see our conditions.