Accumulation of keratinizing squamous epithelium in the middle ear or mastoid — locally destructive, classic for chronic foul otorrhea and conductive loss.
Also known as: cholesteatoma, acquired cholesteatoma, congenital cholesteatoma, primary acquired cholesteatoma
Overview
A non-neoplastic, locally destructive accumulation of keratinizing stratified squamous epithelium within the middle ear, attic, or mastoid. Despite the name, it is not a tumor and contains no cholesterol. Classified as congenital (white mass behind an intact, normal tympanic membrane with no history of otorrhea, perforation, or ear surgery; prior episodes of otitis media do not exclude it) or acquired (most common; arising from retraction pockets or perforations).
Epidemiology
Acquired form is most common in adults aged 30-50, with a male predominance. Congenital form classically presents in children aged 4-6 as a white retrotympanic mass behind an intact tympanic membrane. Strongly associated with chronic eustachian tube dysfunction.
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Question 1EENTEasy
A 25-year-old male has had recurrent episodes of right ear pain and purulent drainage for 3 years. He reports hearing loss and a sensation of fluid. On exam, otoscopy shows a white pearly mass behind the tympanic membrane with erosion of the posterior superior quadrant. The mass appears to have keratin debris. Which of the following is the most likely diagnosis?
ACholesteatoma
BNasopharyngeal carcinoma
COtosclerosis
DAcute otitis media with effusion
ETympanosclerosis
Reveal answer & full explanation
Correct answer: A — Cholesteatoma
ACholesteatoma✓
BNasopharyngeal carcinoma
COtosclerosis
DAcute otitis media with effusion
ETympanosclerosis
Why Cholesteatoma is correct
Keratinizing stratified squamous epithelium trapped in the middle ear and/or mastoid
Acquired type (most common): a pars flaccida retraction pocket from chronic Eustachian tube dysfunction leads to epithelial ingrowth; congenital type is a squamous rest behind an intact drum in children
Expands by shedding keratin debris and producing matrix metalloproteinases that erode bone
Classic otoscopy: white pearly mass with erosion of the posterior superior quadrant, often with chronic foul-smelling discharge and conductive hearing loss
The 3-year history of recurrent drainage plus a pearly, keratin-filled mass fits this diagnosis precisely
Why the others are wrong
Acute otitis media with effusion — right-concept-wrong-setting; effusion gives a dull or amber drum with fluid, not a pearly keratin mass eroding bone
Nasopharyngeal carcinoma — confused-with; it can cause unilateral serous effusion via Eustachian tube blockage, but it presents with a nasopharyngeal mass/epistaxis/neck node, not a keratin ball behind the drum
Otosclerosis — anchoring on conductive hearing loss; otosclerosis causes progressive conductive loss with a normal drum (no mass, no drainage, no erosion)
Tympanosclerosis — confused-with by color; recurrent otitis media can leave chalky white hyalinized plaques in the drum (myringosclerosis) or around the middle-ear ossicles, which may cause conductive hearing loss, but these are inert scars that do not cause active purulent drainage, keratin debris, or erosion of the posterior superior quadrant
Preoperative CT of the temporal bone defines extent and bony erosion
Treatment is surgical (canal-wall-up vs canal-wall-down mastoidectomy); there is no medical cure
Question 2EENTMedium
A 42-year-old man presents with 6 months of foul-smelling drainage from his right ear that has not improved despite three courses of oral antibiotics. He reports gradual hearing loss and aural fullness on that side. His history includes recurrent ear infections as a child and a tympanostomy tube placed years ago. On otoscopy, the pars flaccida shows a defect containing pearly-white keratin debris. Tuning fork testing reveals a conductive hearing loss in the right ear, and high-resolution CT of the temporal bones shows a soft tissue mass with erosion of the scutum and ossicles. Which of the following is the most likely diagnosis?
ADiffuse tympanosclerosis plaque
BAttic retraction cholesteatoma
CMiddle ear cholesterol granuloma
DChronic suppurative otitis media
EGlomus tympanicum paraganglioma
Reveal answer & full explanation
Correct answer: B — Attic retraction cholesteatoma
ADiffuse tympanosclerosis plaque
BAttic retraction cholesteatoma✓
CMiddle ear cholesterol granuloma
DChronic suppurative otitis media
EGlomus tympanicum paraganglioma
Why Attic retraction cholesteatoma is correct
The hallmark triad is chronic foul otorrhea unresponsive to antibiotics, conductive hearing loss, and pearly-white keratin debris in a pars flaccida (attic) defect, all present here.
The apparent pars flaccida defect is usually the opening of a retraction pocket in which keratin accumulates, the typical origin of an acquired attic cholesteatoma.
Trapped keratinizing squamous epithelium releases collagenase and osteoclast-activating cytokines that resorb bone; CT showing scutum blunting and ossicular erosion is the classic radiographic correlate.
His childhood recurrent otitis media and prior tympanostomy tube, both markers of chronic eustachian tube dysfunction, fit the acquired form. Definitive treatment is surgical (tympanomastoidectomy); MRI with non-echoplanar DWI is the surveillance tool for recurrence.
Why the others are wrong
Diffuse tympanosclerosis plaque - chalky white plaques within the tympanic membrane or middle ear cause conductive loss, but tympanosclerosis does not erode bone or produce foul otorrhea.
Glomus tympanicum paraganglioma - a vascular tumor presenting with pulsatile tinnitus and a red retrotympanic mass, not pearly keratin debris or foul drainage.
Chronic suppurative otitis media - causes a persistent central pars tensa perforation with mucopurulent otorrhea but no keratin debris; it can erode the ossicles, but keratin in a pars flaccida defect with scutal erosion points to cholesteatoma.
Middle ear cholesterol granuloma - the similar name invites confusion, and chronic eustachian tube dysfunction predisposes to both, but a cholesterol granuloma is a foreign-body reaction to cholesterol crystals from blood breakdown products that appears as a blue or dark retrotympanic mass, without pearly keratin debris or foul otorrhea.
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Prior tympanic membrane perforation or tympanostomy tube history
Cleft palate and craniofacial anomalies
Trauma to the tympanic membrane
Pathophysiology
Chronic negative middle ear pressure produces a retraction pocket of the pars flaccida (attic) or pars tensa. Squamous epithelium becomes trapped, accumulates keratin, and expands. The keratin matrix produces enzymes (collagenase, osteoclast-activating cytokines) that resorb adjacent bone — leading to ossicular erosion, labyrinthine fistula, and intracranial extension. Secondary bacterial infection (often Pseudomonas, Staphylococcus, anaerobes) causes the characteristic foul otorrhea.
Clinical presentation
Symptoms
Chronic, foul-smelling otorrhea that may persist despite multiple courses of antibiotics
Conductive hearing loss
Aural fullness; occasionally otalgia
Vertigo or imbalance suggests labyrinthine fistula
Facial weakness suggests erosion into the facial canal
Signs / physical exam
Otoscopy: retraction pocket of the pars flaccida (attic) filled with white keratin debris is the classic finding
Marginal or attic perforation with pearly-white debris extruding through the defect
Granulation tissue or polyp obscuring the middle ear
Positive fistula test (vertigo and nystagmus induced by pneumatic otoscopy or tragal pressure) if labyrinthine fistula present
Conductive hearing loss on tuning fork tests
Classic findings
Chronic foul otorrhea unresponsive to antibiotics, conductive hearing loss, and pearly-white debris in an attic retraction pocket.
Differential diagnosis
Chronic suppurative otitis media without cholesteatoma — Persistent perforation with mucoid otorrhea but no keratin debris or retraction pocket; CT shows no mass
Otitis externa — Tenderness on tragal pressure, ear canal edema and discharge, normal middle ear
Tympanosclerosis — Chalky white plaques within the tympanic membrane or middle ear; conductive loss without erosion
Glomus tumor (paraganglioma) — Pulsatile tinnitus, vascular red mass behind tympanic membrane, audible bruit; MRI with contrast
Middle ear adenoma or carcinoma — Rare; persistent mass that fails to resolve; biopsy
Granulation tissue from chronic infection — Friable bleeding tissue in the middle ear; resolves with treatment of infection
Diagnostic workup
Diagnostic criteria
Clinical diagnosis supported by otoscopy and imaging: keratin debris in a retraction pocket or perforation, with CT evidence of soft tissue mass and bony erosion.
Labs
Culture of otorrhea — typically polymicrobial, often Pseudomonas aeruginosa and Staphylococcus aureus
No routine systemic labs
Imaging
High-resolution CT of the temporal bones — defines extent, ossicular and otic capsule erosion, scutum blunting, tegmen integrity, facial canal status; preoperative imaging of choice
MRI with non-echoplanar diffusion-weighted imaging — distinguishes cholesteatoma (bright on DWI) from granulation tissue or fluid; used for postoperative surveillance to detect residual or recurrent disease
Pure tone audiogram to document baseline hearing and air-bone gap
Diagnostic algorithm
flowchart TD
A[Chronic foul otorrhea<br/>+ hearing loss] --> B[Otoscopy]
B --> C{Attic retraction<br/>or perforation<br/>with keratin debris?}
C -->|Yes| D[Suspect cholesteatoma]
D --> E[CT temporal bone<br/>+ audiogram]
E --> F[Topical antibiotic/steroid<br/>aural toilet]
F --> G[Tympanomastoidectomy]
G --> H[Second-look surgery<br/>or DWI-MRI<br/>at 9-12 months]
C -->|No| I[Treat as CSOM<br/>or otitis externa]
Workup and management of suspected cholesteatoma.
Treatment
First-line
Surgical removal is definitive — tympanomastoidectomy (canal wall up or canal wall down) with goals of complete disease eradication, dry safe ear, and hearing preservation when possible
Aural toilet and topical antibiotic-steroid drops (e.g., ciprofloxacin-dexamethasone) to control acute infection prior to surgery
Ossicular reconstruction at the time of primary surgery or as a staged second-look procedure
Second-line / adjunct
Canal wall down mastoidectomy preferred for extensive disease, only-hearing ear, recurrent disease, or labyrinthine fistula
Second-look surgery or follow-up MRI with DWI 9-12 months postoperatively to detect residual disease
Hearing aid or implantable device if hearing cannot be restored surgically
Complications
Ossicular erosion (the most common complication; classically the long process of the incus) with conductive or mixed hearing loss
Labyrinthine fistula with sensorineural hearing loss and vertigo
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