Cholesteatoma is an abnormal collection of squamous epithelial cells in the middle ear. It is non-cancerous but can invade local tissues and nerves and erode the bones of the middle ear. It can predispose to significant infections.
Confusingly, cholesteatoma has nothing to do with cholesterol or a tumour.
The pathophysiology is not fully understood. Squamous epithelial cells originate from the outer surface of the tympanic membrane. The main theory is that negative pressure in the middle ear, caused by Eustachian tube dysfunction, causes a pocket of the tympanic membrane to retract into the middle ear. Essentially, a small area of the tympanic membrane gets sucked inwards. The squamous epithelial cells of this pocket continue to proliferate and grow into the surrounding space, bones and tissues. It can damage the ossicles (the tiny bones of the middle ear involved in hearing), resulting in permanent hearing loss.
The typical presenting symptoms are:
- Foul discharge from the ear
- Unilateral conductive hearing loss
As the cholesteatoma continues to expand into the surrounding spaces and tissues, further symptoms may develop, including:
- Facial nerve palsy
Otoscopy can show an abnormal build-up of whitish debris or crust in the upper tympanic membrane. However, it may not be possible to visualise the eardrum if discharge or wax are blocking the canal.
A CT head can be used to confirm the diagnosis and plan for surgery. MRI may help assess invasion and damage to local soft tissues.
Treatment involves surgical removal of the cholesteatoma.
Last updated July 2021