Cholesteatoma (active squamous chronic otitis media

Question 1

What is the pathophysiology of cholesteatoma?

Answer 1

• Negative pressure in middle ear causes pars flaccida to balloon backwards (attic/retraction pocket) -> migratory epithelium of outer layer of tympanic membrane grows & falls into pocket
• Collection of squamous material (still dividing!) from the external ear found within the mucosal area, and it cannot be cleared (becomes stuck). If it could be cleared, it would not be a problem.
• Gradual enlargement and build-up of squames ( +/- infection w Pseudo) -> problems -> inflamm causes bony erosions upwards (into attic) and backwards (into mastoid)

Question 2

What are the symptoms of cholesteatoma?

Answer 2

• *Foul-smelling otorrhoea (most common)

- CHL (w/ ossicle involvement)

Question 3

What are the signs of cholesteatoma?

Answer 3

• Attic retraction, filled w/ squamous debris (white squames)
• May have crusting over the squames, blocking the white squames from view
• Discharging attic perforation
• Attic aural polyp
• Post-auricular scar seen on pt: could indicate prev mastoidectomy. Usually facial ridge should be drilled such that the squames accumulation in mastoid can be removed via EAC.

Question 4

What are the complications of cholesteatoma?

Answer 4

Middle ear issues (a lot more common in SG)

• Facial nerve palsy (CN7 involvement, but note that facial nerve is q robust and is rarely affected in cholesteatoma unless in a particularly bad case)
• Can destroy ossicles 🡪 CHL
• Lead to mastoiditis (creation of fistula by invasion)

Inner ear involvement:

• SNHL
• Vertigo (erosion of lateral horizontal semicircular canal due to extension into middle ear, labyrinthitis (contiguous infection), perilymphatic fistula (erosion into superior semicircular canal [SCC]))
• Fistula sign: thumb presses against ear/tragus (raise pressure) will get nystagmus in the direction of the pressure, when release then will nystagmus in opposite direction. Will feel vertigo throughout. Assesses for Labyrinthine Fistula (which is due to erosion of the bony labyrinth by cholesteatoma)
• Infection of inner ear

Intracranial involvement: spread from labyrinth

• Temporal lobe abscess, Occipital lobe abscess
• Frontal sinusitis
• intracranial sepsis (due to erosion of tegmen, which is a part of temporal bone, providing passage for pathogens to enter cranial cavity)
• Meningitis

Question 5

What are the investigations to be done for cholesteatoma?

Answer 5

• CT temporal bone, mastoid, IAM, TMJ (watch for tegmen erosion & intracranial extension)
• MRI (soft tissue detail) MRI DWI can distinguish cholesteatoma from other middle ear masses, also assesses semicircular canals, facial nerve

Question 6

What is the management of cholesteatoma?

Answer 6

May not need Sx if

• Cholesteatoma erodes out (and creates a passage)
• Cholesteatoma can be removed by forceps and suction
• Ear can be kept clean and non-infected w regular aural toilet

If not, surgical removal: ranges from atticotomy (if limited) to modified radical mastoidectomy

• Consider reconstruction of hearing mechanism at a later stage
• May be complicated by brain abscess, meningitis, etc (generally same as Cx of AOM)