Cholesteatoma

Definition:

• Abnormal extension of keratinizing squamous epithelium into the middle ear and mastoid air cell spaces.

Clinical Presentation:

• Initially asymptomatic.
• Conductive hearing loss.
• Intermittent ear discharge.
• Changes on otoscopic examination, most commonly superior and posterior, showing a retraction pocket with or without debris, granulation tissue, or granular polyp.
• Advanced cases may present with facial nerve weakness, vertigo, inner ear invasion, or intracranial infection.

Examination:

• Otoscopy reveals a perforation or retraction pocket of the tympanic membrane.
• Always examine the facial nerve function.

Pathogenesis:

Congenital Cholesteatoma:

• Arises from embryonal nests of epithelial cells.
• Typically presents at ages 4-5, more common in males.
• Appears as a spherical white mass behind an intact tympanic membrane.
• Causes conductive hearing loss.

Acquired Cholesteatoma:

• More common in adults.
• Often originates from a retraction pocket within the tympanic membrane due to underlying Eustachian tube dysfunction or recurrent otitis media.
• Keratin accumulates in this sac, rarely from the migration of skin cells through a perforation.
• Grommets may offer some protection.
• Proteolytic enzymes produced by the keratinizing squamous epithelium can destroy the incus, stapes, and cochlea, extending to balance centers and leading to complications like abscess and mastoiditis.
• The condition can threaten the tegmen (bony plate separating the middle ear from the cranium).
• Hearing loss occurs as ossicles are engulfed, although some sound transmission might persist.
• Acute infection can lead to otorrhea; if otitis media fails to resolve with antibiotics, suspect cholesteatoma.

Differential Diagnosis:

• Osteoma of the ear canal.
• Tympanosclerosis (scarring).
• Other perforations and retractions (safe if centrally located and not involving the fibrous edge, with no white mass or granulation tissue).
• Malignancy of the ear canal.

Investigations:

• Audiogram: To identify conductive hearing loss; if sensorineural loss is present, suspect inner ear involvement.
• CT of the temporal bone: To assess the extent of disease and involvement of surrounding structures.

Management:

• Surgical intervention is typically required.
• Referral to an otolaryngologist for appropriate management and surgical planning is essential.