Cholesteatoma

Overview

Cholesteatoma is an accumulation of desquamating keratin-producing squamous epithelium within the middle ear cleft - locally destructive via enzymatic osteoclast activation, threatening the ossicular chain, facial nerve, labyrinth, and intracranial structures.

Risk factors

•Eustachian tube dysfunction - the central risk factor for acquired disease

•Recurrent acute otitis media / chronic otitis media with effusion (glue ear)

•Tympanic membrane perforation - allows ingrowth of squamous epithelium

•Cleft palate - impaired Eustachian tube function, especially in children

•Previous ear surgery

Presentation

•Otorrhoea - unilateral, persistent, foul-smelling, does not respond to topical antibiotics (hallmark)

•Hearing loss - usually conductive (ossicular erosion); progresses to mixed/sensorineural if labyrinth involved

•Aural fullness, tinnitus, mild otalgia

•Vertigo - suggests labyrinthine erosion (complication)

•Facial weakness - indicates facial nerve involvement; red flag requiring emergency referral

•Otoscopy findings: retraction pocket (pars flaccida/attic region), white pearly keratin debris, marginal or attic perforation, granulation tissue/polyps; congenital type shows white mass behind intact tympanic membrane

⚠️

Persistent unilateral otorrhoea failing two adequate courses of appropriate treatment must trigger ENT referral - do not assume recurrent otitis externa. Always visualise the tympanic membrane; if it cannot be seen, refer.

Investigations

🥇 First-line

•otoscopy - retraction pocket, keratin debris, marginal/attic perforation

•Audiometry (pure tone audiogram) - defines type and degree of hearing loss; essential for surgical planning

•Gold standard (surgical planning): CT temporal bones (non-contrast) - delineates bony erosion of ossicular chain, tegmen, facial nerve canal

•MRI temporal bones (non-EPI DW-MRI) - detects residual/recurrent disease post-operatively without radiation

💡

CT cannot reliably distinguish cholesteatoma from cholesterol granuloma or other middle ear masses - definitive diagnosis is confirmed histologically at surgery.

Management

•Definitive treatment: surgical excision - the only cure; no medical treatment exists

•Temporising (pre-referral only): ciprofloxacin ear drops - reduces active infection/discharge but does not treat cholesteatoma and must not delay referral

•Urgent same-day emergency admission for red flag complications (see below)

Follow-up

•Long-term ENT follow-up essential - significant recurrence risk; residual keratin may be left at surgery

•Non-EPI DW-MRI at defined intervals (e.g. 12-18 months post-surgery) to detect residual/recurrent disease

•Second-look surgery may be planned after canal wall up mastoidectomy

•Canal wall down (mastoid cavity) patients require regular aural toilet (microsuction)

Complications

•Conductive hearing loss - most common; ossicular chain erosion (long process of incus most vulnerable)

•Sensorineural hearing loss / labyrinthitis - erosion of bony labyrinth (horizontal semicircular canal most vulnerable)

•Facial nerve palsy - erosion of horizontal/tympanic segment of facial nerve canal; ipsilateral LMN pattern; surgical emergency

•Mastoiditis - post-auricular tenderness, erythema, pinna displaced anteroinferiorly

•Intracranial complications - meningitis, extradural/subdural/brain abscess, sigmoid sinus thrombosis, cavernous sinus thrombosis

🚨

Same-day emergency admission required for: facial nerve palsy (LMN pattern), severe headache/meningism, neurological signs or altered consciousness, acute severe vertigo or sudden sensorineural hearing loss, signs of mastoiditis (post-auricular swelling, displaced pinna).