What is Cholesteatoma?
Cholesteatoma is an abnormal, noncancerous growth of keratinizing squamous epithelium that develops in the middle ear, forming a cystic structure that accumulates dead skin cells (keratin debris) and progressively destroys surrounding bone structures through enzymatic activity and pressure effects. 1, 2
Pathophysiology and Formation
Cholesteatoma represents a destructive pseudotumor consisting of keratinized squamous epithelium that produces keratin masses within the temporal bone 3. The trapped keratinous debris becomes secondarily infected with polymicrobial bacterial flora, most commonly including Haemophilus influenzae, Staphylococcus aureus, and Pseudomonas aeruginosa 1, 2.
Routes of Development
- Posterior epitympanic cholesteatoma accounts for 32.9% of cases 4
- Posterior mesotympanic cholesteatoma represents 33.7% of cases and is the most frequent type 4
- Anterior epitympanic cholesteatoma comprises only 1.9% of cases 4
- Multiple routes occur in 14.8% of patients 4
- Traumatic implantation can occur following tympanostomy tube placement 2
Relationship to Chronic Otitis Media
Cholesteatoma occurs in the context of chronic suppurative otitis media (CSOM), which is defined as chronic inflammation of the middle ear and mastoid mucosa with a non-intact tympanic membrane and persistent ear discharge 5. The prevalence of cholesteatoma in patients with chronic otitis media is 24.5%, making it a common complication 4. CSOM with cholesteatoma of large duration is associated with cholesteatoma in 31.3% of patients regardless of the location of tympanic defect 6.
Clinical Presentation
Primary Symptoms
- Foul-smelling, purulent ear discharge is the hallmark presentation, occurring in 100% of extensive cases 1, 7
- Hearing loss (conductive type) is present in 83.33% of patients 7
- Characteristically painless unless complications develop, distinguishing it from acute otitis media 1
- Tinnitus and ear fullness are common but nonspecific associated symptoms 1
Physical Examination Findings
- Tympanic membrane abnormalities including retraction pockets, perforation, or white keratinous debris visible behind an intact membrane 1
- Granulation tissue at sites of erosion 1
- Attic blockage and scutum erosion on careful examination 1
Progressive Destructive Effects on the Middle Ear
Cholesteatoma causes extensive bone erosion through enzymatic activity and pressure effects, leading to multiple complications 2:
Structural Damage
- Ossicular erosion affecting the malleus, incus, and stapes 2
- Scutum erosion in the epitympanic region 2
- Lateral semicircular canal erosion threatening vestibular function 2
- Facial canal dehiscence risking facial nerve injury 2
- Tegmen erosion (66.66% of extensive cases), potentially leading to intracranial complications 2, 7
Serious Complications
- Sigmoid sinus thrombosis occurred in 16.66% of extensive cases 7
- Cerebellar abscess requiring drainage in some patients 7
- Petrositis in 8.33% of cases 7
- Brain hernia or cerebrospinal fluid leakage from tegmen erosion 7
Critical Distinction from Other Forms of Otitis Media
Cholesteatoma should not be confused with simple acute otitis media or ventilation tube-associated otorrhea, as it requires surgical management rather than medical therapy 1. Unlike acute otitis media, which presents with rapid onset of ear pain, fever, and bulging tympanic membrane 8, cholesteatoma is painless and characterized by the presence of white keratinous debris 1.
Management Imperative
Surgical excision is the only effective treatment for cholesteatoma, as there are no effective nonsurgical options currently available 2, 9. Any patient with suspected cholesteatoma should be referred immediately to an otolaryngologist for definitive surgical management 1. The most common surgical approach is open tympanomastoidectomy (75.2% of cases), though closed tympanomastoidectomy is used in 16.8% 4. Despite precise surgical technique, recurrence is relatively frequent, especially in childhood 3.
Common Pitfalls
The key clinical pitfall is mistaking cholesteatoma for simple chronic otitis media or acute otitis media, which delays appropriate surgical referral and allows progressive bone destruction 1. The painless nature of cholesteatoma can falsely reassure clinicians, but the foul-smelling discharge and visible white debris should prompt immediate otolaryngology consultation 1. Early surgical intervention during the remission phase significantly reduces disease extension and permits middle ear reconstruction in 70% of patients 6.