ENT clinic - cholesteatoma

Case

This 16-year-old man had presented with otorrhoea in his right ear twice in the previous nine months. On both occasions he had been diagnosed with otitis externa and treated with topical gentamicin and hydrocortisone. The tympanic membrane had not been visualised at either visit.

He now presents with the same symptoms but also complaining of hearing loss, which prompts him to be referred to an ENT GPSI. The auditory canal was carefully cleaned out and a cholesteatoma was found in the tympanic membrane. He was referred to ENT and a CT scan was performed to evaluate the extent of the lesion, which was successfully removed by mastoidectomy.

The problem

A cholesteatoma is a destructive and expanding lesion of the middle ear or mastoid process, consisting of keratinising squamous epithelium.
It can be a congenital condition, but most are acquired and their precise aetiology is unknown.
It tends to originate in the lateral epithelium of the tympanic membrane and then grow into the middle ear, but can also erode into the inner ear causing sensorineural hearing loss or vertigo.
Incidence in Europe is estimated at 9.2 per 100,000 population a year.¹
It is often misdiagnosed as otitis media in children and otitis externa in adults. Negligence claims against GPs have been successful.

Features

Onset tends to be insidious and symptoms may be intermittent or mild.
Typically presents with intermittent unilateral otorrhoea and progressive hearing loss.
Acquired cholesteatoma can occur at any age, but peak incidence is between five and 15 years.²
Congenital cholesteatoma usually presents in childhood – six months to five years – but may present in adulthood.
Small lesions cause progressive hearing loss, but as they grow into adjacent structures they can cause vertigo, headache and facial nerve palsy.
Most lesions develop in the attic, but they can also be found in the lower part of the membrane.

Diagnosis

Symptoms are non-specific and the diagnosis relies on otoscopy – typically visualised as a yellow-white crust in the tympanic membrane.
GPs should suspect cholesteatoma when otorrhoea does not respond to treatment or keeps recurring.
Only visualisation of the whole tympanic membrane can exclude cholesteatoma, but discharge and oedema may make that impossible.
If aural toilet is not possible in the practice, consider treating for a presumed infection and examining the patient again when there is less discharge.
If visualisation is still not possible, refer for cholesteatoma to be excluded.

Management

Any patient with diagnosed or suspected cholesteatoma should be referred urgently.
Once the diagnosis is confirmed, the extent of the lesion will be assessed by a CT or – if soft tissue involvement is suspected – an MRI.
Treatment is by surgical excision and the technique used is largely dependent on the lesion size and the patient's age.
Life-long follow-up is required, as cholesteatomas may recur, especially if congenital.

Dr Raj Singh is an ENT GPSI in Manchester

References

1 Kemppainen HO, Puhakka HJ, Laippala PJ et al. Epidemiology and aetiology of middle-ear cholesteatoma. Acta Otolaryngol 1999;119:568-72

2 Roland PS. Middle ear, cholesteatoma. Medscape 2009. http://emedicine.medscape.com/article/860080-overview (Accessed 10 February 2012)