Examqo › Examqo library › Otolaryngology – Head and Neck Surgery › Otology and lateral skull base · IMLE
Cholesteatoma
Cholesteatoma is keratin-producing squamous epithelium in the wrong place — the middle ear and mastoid — that grows while destroying bone through enzymes and cytokines; treatment is surgical only, and follow-up afterwards (a "second-look" operation or diffusion-weighted MRI) is part of the treatment.
Why it matters in the exam
The exam asks about pathogenesis and types. Congenital cholesteatoma is a white mass behind an intact eardrum, usually in the anterosuperior quadrant, in a child without a history of infections or surgery. Primary acquired cholesteatoma arises from a retraction pocket, usually in the pars flaccida, into Prussak space — bounded laterally by the pars flaccida, medially by the neck of the malleus, and below by the short process of the malleus. Secondary acquired cholesteatoma arises from epithelial migration through a marginal perforation or from implantation during surgery. The theories: invagination, migration, metaplasia and basal cell hyperplasia.
Bone destruction comes from osteoclasts activated by cytokines such as RANKL, TNF-α and IL-1. The bone most often destroyed first is the long process of the incus, whose blood supply is poor. Complications: fistula of the lateral semicircular canal (vertigo with pressure on the ear — fistula test), facial nerve palsy, sensorineural hearing loss and intracranial complications. The typical complaint: chronic foul-smelling ear discharge that does not respond to drops, with conductive hearing loss.
CT of the temporal bone shows the extent of destruction and the structures at risk; non-echo-planar diffusion-weighted MRI (non-EPI DWI) detects residual or recurrent cholesteatoma. In a canal wall up operation the posterior canal wall is kept, so a second-look operation after 6 to 12 months or diffusion-weighted MRI is needed; a canal wall down operation leaves an open cavity that needs regular cleaning for life, but recurrence is lower.
Key points
- Squamous epithelium in the middle ear that destroys bone.
- Congenital: white mass behind an intact eardrum.
- Primary acquired: pars flaccida pocket and Prussak space.
- The long process of the incus is destroyed first.
- Surgery only; second look or non-EPI DWI MRI.
Summary table
| Type | Clue | Treatment and follow-up |
|---|---|---|
| Congenital | White mass behind an intact eardrum, anterosuperior quadrant | Surgical removal |
| Primary acquired | Retraction pocket in the pars flaccida, Prussak space | Mastoidectomy and eardrum repair |
| Secondary acquired | Marginal perforation or after surgery | Surgical removal |
| Canal wall up | Canal wall kept | Second look after 6 to 12 months or non-EPI DWI MRI |
| Canal wall down | Open cavity | Regular cleaning for life, less recurrence |
In the full version for subscribers
- A simple algorithm
- Memory aid
- Exam traps
- 5 review cards
- Enough for IMLE
The full version is open to subscribers of: ENT and head and neck surgery, Medical licensing exam (IMLE), Pediatrics.
Subscriber? Read the full topic Plans and prices 25 free questions
Sources
- EAONO/JOS Joint Consensus Statements on the Definitions, Classification and Staging of Middle Ear Cholesteatoma, 2017 — Definitions and staging
- Cummings Otolaryngology: Head and Neck Surgery, 7th edition (2021) — Chronic otitis media, mastoiditis and petrositis; cholesteatoma
- Glasscock-Shambaugh Surgery of the Ear, 7th edition (2022) — Cholesteatoma: pathogenesis and surgery
Sources are given for further reading; the text is written afresh and not copied from them.
Reviewed by the Examqo AI Professor · 2026-11-06. The text may contain errors; when in doubt, check the source.