What is a cholesteatoma, how does it form, and what are its symptoms?

Cholesteatoma: Definition, Formation, and Symptoms

A cholesteatoma is a benign but potentially destructive growth of keratinizing squamous epithelium in the middle ear that can erode surrounding structures if left untreated. Cholesteatomas are typically painless but can cause progressive hearing loss, drainage from the ear, and serious complications if not properly managed by an otolaryngologist.

What is a Cholesteatoma?

Cholesteatoma is an abnormal, noncancerous skin growth that appears as a cyst or sac in the middle ear, containing accumulated layers of dead skin cells 1. Despite its name (which contains "chol-" suggesting fat and "-oma" suggesting tumor), it is neither fatty nor truly neoplastic. It is essentially a misplaced growth of skin that doesn't belong in the middle ear space.

How Cholesteatomas Form

Cholesteatomas can form through several mechanisms:

1. Acquired Cholesteatoma (most common):

   • Develops from a retraction pocket in the tympanic membrane, typically in the pars flaccida or posterosuperior quadrant of the pars tensa 2
   • Often begins with Eustachian tube dysfunction causing negative middle ear pressure
   • Chronic/recurrent middle ear infections are a major contributing factor
   • The retracted portion of the eardrum can't clear dead skin cells normally, leading to accumulation

2. Congenital Cholesteatoma:

   • Present at birth due to embryonic epithelial rests trapped during development
   • Less common than acquired cholesteatomas

3. Secondary Cholesteatoma:

   • Develops after skin enters the middle ear through a perforation in the tympanic membrane
   • Can occur after trauma or surgery

Common Symptoms

Cholesteatomas typically present with:

1. Otorrhea (ear drainage):

   • Foul-smelling, purulent discharge is very common 3
   • Often persistent despite treatment

2. Hearing Loss:

   • Progressive conductive hearing loss due to:
     • Disruption of the ossicular chain
     • Blockage of the middle ear space

3. Otalgia (ear pain):

   • May be present, especially with infection 3

4. Vertigo/Dizziness:

   • Can occur if the cholesteatoma erodes into the inner ear 3

5. Tinnitus (ringing in the ears)

6. Facial Weakness/Paralysis:

   • A late complication if the facial nerve becomes involved

Diagnosis

Diagnosis is primarily clinical, based on otoscopic examination. Key findings include:

• White or yellowish mass behind the tympanic membrane
• Retraction pockets in the tympanic membrane
• Perforation with visible keratin debris
• Granulation tissue

Imaging (CT and MRI) is used to determine the extent of disease and identify complications 4.

Complications

If left untreated, cholesteatomas can lead to serious complications:

1. Ossicular chain erosion - causing conductive hearing loss
2. Labyrinthine fistula - causing vertigo and sensorineural hearing loss
3. Facial nerve paralysis - from erosion of the facial nerve canal
4. Intracranial complications:
   • Meningitis
   • Brain abscess
   • Sigmoid sinus thrombosis 3
5. Tegmen erosion - potentially leading to cerebrospinal fluid leak or brain herniation 3

Management

The definitive treatment for cholesteatoma is surgical removal. The primary goal is to create a safe, dry ear by removing all disease 2. Surgical approaches include:

1. Canal wall up (intact canal wall) mastoidectomy
2. Canal wall down mastoidectomy
3. Combined approaches

Regular follow-up is essential due to the risk of recurrence or residual disease.

Important Considerations

• Any patient with suspected cholesteatoma should be referred to an otolaryngologist for definitive management 5
• Cholesteatomas can be mistaken for acute otitis externa but are typically painless and associated with tympanic membrane abnormalities 5
• Unlike many middle ear conditions, cholesteatomas cannot be treated medically and require surgical intervention
• Early diagnosis and treatment are crucial to prevent serious complications