OVERVIEW

What is a cholesteatoma?

A cholesteatoma is a mass-like lesion composed of squamous epithelium, keratin, and small amounts of cholesterol crystals encapsulated by fibrous connective tissue. It is also known as a dermoid cyst or pearly tumor.

It commonly occurs in the ear and brain. Although not a true tumor, it can erode surrounding bone and cause severe adverse reactions. Based on the location of occurrence, it can be classified into three types: intracranial cholesteatoma, external auditory canal cholesteatoma, and cholesteatoma otitis media.

Is cholesteatoma hereditary?

The exact cause of cholesteatoma remains unclear. While there may be some genetic correlation, it is also associated with allergies and inflammation of the upper respiratory tract. Whether parents with cholesteatoma will pass it on to their children has not yet been definitively determined.

SYMPTOMS

What are the manifestations of cholesteatoma?

• Intracranial cholesteatoma: Commonly occurs in areas such as the cerebellopontine angle, sellar region, and middle cranial fossa, which may compress surrounding nerves and brain tissue.

• When compressing the cerebellopontine angle, symptoms may include trigeminal neuralgia, diminished corneal reflex, facial hypoesthesia, facial muscle spasms, and may also be accompanied by tinnitus and hearing loss.

• When compressing the sellar region, progressive vision loss and visual field defects may occur, and pituitary function may also be affected, with some patients experiencing sexual dysfunction.

• When compressing the middle cranial fossa, trigeminal and facial nerve dysfunction, masticatory muscle weakness, as well as vision, visual field, and eye movement disorders may occur.

• External auditory canal cholesteatoma: External auditory canal cholesteatoma can not only destroy the bony walls of the external auditory canal but also invade middle ear structures such as the epitympanum and mastoid, with lesions potentially extending to the facial nerve and extratemporal structures. Clinical manifestations include hearing loss, ear pain, otorrhea, ear fullness or tinnitus, and ear bleeding. If cranial nerves or surrounding tissues are involved, symptoms such as facial paralysis, dizziness, or limited mouth opening may occur.

• Cholesteatomatous otitis media: Cholesteatomatous otitis media commonly occurs in the epitympanum and mastoid antrum, where cholesteatoma often erodes the short process and body of the incus. Clinical manifestations include long-term purulent ear discharge, sometimes with a foul odor or hearing loss, and some patients may experience dizziness. The symptoms of this condition are distinctive and may lead to complications such as intracranial infection, meningitis, and other inflammatory conditions.

CAUSES

How does cholesteatoma form?

During embryonic development, the ectoderm typically develops into skin covered with squamous epithelium. If ectodermal tissue remains in areas like the middle ear cavity or petrous apex during embryonic development, congenital cholesteatoma may form. Congenital cholesteatoma is relatively rare.

The more commonly encountered cholesteatomas are acquired. They often result from chronic inflammation, infection, foreign bodies, or tumor compression, which obstruct the discharge of metabolic products like squamous epithelium and keratinized epithelium. These substances accumulate in the ear canal, middle ear, or even around brain tissue, forming a mass. Over time, necrotic material at the center of the mass degenerates, producing cholesterol crystals and forming a cholesteatoma.

Can cholesteatoma occur due to failure to clean earwax promptly?

The ear canal naturally produces earwax (cerumen), which usually discharges on its own without requiring manual cleaning.

However, some individuals produce excessive earwax, which can accumulate in the ear canal and form a tightly packed mass. This blockage can impair hearing and, more critically, hinder the self-cleaning ability of the deeper epithelial layers, trapping metabolic waste and potentially leading to cholesteatoma formation.

That said, external auditory canal cholesteatoma is not solely caused by earwax blockage. It also relates to individual predispositions—some people are more prone to developing cholesteatomas, while others may experience earwax blockage without developing the condition.

Can ear trauma cause cholesteatoma?

The likelihood of cholesteatoma resulting from ear trauma is very low, but it remains a possibility. This includes iatrogenic injuries (e.g., during medical procedures) or direct trauma-related cases.

For example, during tympanocentesis (ear fluid drainage) or myringotomy (eardrum incision), squamous epithelium may inadvertently be introduced into the middle ear cavity, increasing cholesteatoma risk.

Similarly, traumatic eardrum perforations that fail to heal may allow epithelial tissue from the perforation edges or squamous epithelium to migrate into the middle ear, potentially leading to cholesteatoma—though this is exceptionally rare.

DIAGNOSIS

How is cholesteatoma diagnosed?

The diagnosis of cholesteatoma requires a combination of clinical symptoms, hearing tests, electromyography, and imaging examinations such as CT and MRI. Otoscopy can also be performed to observe the presence of inflammation, suppuration, or fistula formation.

• If experiencing ear fullness or hearing loss, an ENT examination is recommended. If the patient presents with ear discharge (pus or blood) accompanied by a foul odor, cholesteatoma should be considered.

• Audiological tests often reveal hearing loss or deafness in pure-tone audiometry, absence of stapedius reflex, and difficulty eliciting the V-wave response.

• Vestibular function: Possible reduced response in the horizontal semicircular canal.

• Facial nerve electromyography may indicate partial facial nerve damage.

• MRI (plain + contrast): May show abnormal oval-shaped signal shadows with enhanced edges on contrast scans.

• CT imaging + 3D reconstruction: Widening of the bony canal at the apex of the internal auditory meatus, bone absorption/destruction, and soft tissue density shadows filling the tympanic cavity, mastoid antrum, and mastoid cells. Partial involvement of the ossicular chain may occur. Surgical biopsy, if necessary, may reveal an enlarged tympanic cavity containing white cholesteatoma, granulation tissue, destruction of the malleus head and part of the incus body, and tympanic membrane perforation.

What diseases should cholesteatoma be differentiated from?

• Simple tympanic membrane perforation: Caused by various ear inflammations, resulting in a dry perforation—similar to a hole in the eardrum—without bone destruction, only mucosal lesions.

• Osteitis-type otitis media: Cholesteatoma-type otitis media should be distinguished from osteitis-type otitis media. Both involve bone inflammation and destruction, but surgical biopsy of osteitis-type otitis media shows no cholesteatoma formation. The presence of cholesteatoma indicates cholesteatoma-type otitis media or middle ear cholesteatoma.

• Middle ear cancer: Occurs in the middle ear, primarily manifesting as bleeding or blood-tinged pus. Pathological biopsy reveals malignant cells.

TREATMENT

What is the main treatment for cholesteatoma?

Drug therapy has very limited clinical value for cholesteatoma. Surgery remains the primary treatment. Early detection and surgery are crucial to prevent intracranial and extracranial complications, protect brain tissue, and preserve the ossicles and cranial nerves.

After surgical removal of the cholesteatoma, muscle flaps or bone flaps can be used to fill or seal the cavity. The tissue damage caused by cholesteatoma is often irreversible, but early surgery can help preserve the integrity of the ossicles and restore hearing. Otherwise, if all three ossicles are destroyed, hearing reconstruction becomes very difficult.

How long does it take for cholesteatoma patients to recover after surgery?

Surgery for cholesteatoma in the external auditory canal or middle ear typically takes two to three hours, or up to three to four hours at most. After the procedure, the patient's condition should be monitored for symptoms such as facial paralysis or dizziness. Broad-spectrum antibiotics are usually administered for about three days. Sutures can be removed after one week, followed by regular wound care.

Depending on the extent of the lesion and the size of the cavity, full recovery generally takes one to three months. However, if the surgery is delayed and severe complications such as facial paralysis or brain tissue damage occur, recovery may be more difficult.

What should be noted after cholesteatoma surgery?

• After ear surgery, regular follow-ups are necessary. If there is any discharge, it should be cleaned promptly. Once the epithelium heals, any remaining crusts should also be removed periodically.

• For the first three months, avoid getting water in the ear canal to prevent infection. Alcohol can be used to disinfect the ear opening.

• Avoid flying, diving, or taking high-speed trains within three months, as sudden pressure changes may tear the surgical wound.

• Avoid spicy foods. Patients with gastric issues should manage them promptly to prevent acid reflux, which may cause eustachian tube inflammation.

• Strengthen physical exercise to improve overall immunity and prevent recurrent upper respiratory infections.

Can cholesteatoma be treated without surgery?

Surgery is generally recommended once cholesteatoma is diagnosed, except for very early-stage micro-lesions that respond well to drainage. However, even in such cases, patients in remote areas without medical supervision should consider early surgery. If the patient's other ear already has hearing loss and relies on the affected ear, conservative treatment may be an option, but this is extremely rare.

Medication cannot stop the progression of cholesteatoma. Frequent use of anti-inflammatory drugs or ear drops is not recommended, as cholesteatoma grows faster in moist environments. Dehydrating agents like boric acid or alcohol may temporarily control infection.

Surgery remains the best solution for resolving issues like pus discharge and hearing loss. Conservative treatment is only suitable for very few cases. For young patients, especially children, cholesteatoma progresses faster, so early surgery is strongly advised.

Why is early treatment better for cholesteatoma?

Cholesteatoma is potentially dangerous. While it is a benign lesion, it slowly erodes surrounding bone, particularly the ossicles. Early detection and surgical removal of the lesion, along with tympanic membrane repair, can preserve hearing and other tissue functions while reducing the risk of intracranial infections, facial paralysis, dizziness, and other complications.

Since the 1950s, microscopes have been used in otologic microsurgery, allowing precise lesion removal while protecting surrounding tissues. For experienced surgeons, early-stage cholesteatoma can be completely eradicated with excellent prognosis.

Can cholesteatoma be completely removed? Will it recur?

With advanced microscopes and endoscopic techniques, modern otologic surgery ensures thorough removal of cholesteatoma, including its matrix and surrounding capsule. Any residual epithelial tissue can lead to recurrence.

Recurrence is costly, as a second surgery is more difficult due to scar tissue and increased risk of facial nerve damage. Some cholesteatomas may invade the brain, making them harder to detect and more prone to recurrence.

Which location of cholesteatoma is more severe?

Cholesteatoma in the external auditory canal (external ear cholesteatoma) is easier to detect and usually less severe.

If it spreads to the middle ear, the condition becomes more serious. Erosion into the mastoid is moderately severe, while invasion of brain tissue is highly severe.

Middle ear cholesteatoma near the ossicles is relatively mild, but extensive destruction is moderate. If it extends beyond the middle ear, affecting the brain, balance organs, or facial nerve, severe complications may arise.

Petrous apex cholesteatoma is particularly dangerous if it causes neurological dysfunction or adheres to critical structures like the brain. Early surgery is essential in such cases.

DIET & LIFESTYLE

None.

PREVENTION

How to Prevent Cholesteatoma?

• Patients who develop eustachian tube inflammation after radiotherapy for nasopharyngeal cancer may experience tympanic effusion, increasing the risk of cholesteatoma. Therefore, such patients should undergo regular ENT follow-ups.

• Avoid frequent upper respiratory infections, rhinitis, or sinusitis. Children prone to recurrent colds should be monitored for tympanic retraction, which requires prompt treatment to prevent cholesteatoma formation.

• Patients with a history of otitis media should remain vigilant. If purulent discharge increases, oral antibiotics should be taken to control acute infection, followed by local suction of pus and cleaning with hydrogen peroxide or sterile water.