Tuesday, 27 October 2015

Cholesteotoma

Please note that the following is a general guideline only. For a full assessment, exclusion of any other underlying cause for your symptoms and an individualised treatment approach, you will need to be seen by a qualified specialist.









Definition

Epidermoid cyst in the temporal bone which has the ability to destroy bone and invade.

Incidence

Unknown → estimated 3-6 per 100,000
Congenital about 1/Million-on the rise
Increased incidence in patients with cleft palate and children predisposed to CSOM

Etiology-Theories


1) Retraction pocket: usually occurs in the superior aspect of the tympanic membrane. The pocket leads to accumulation of keratin and eventually a epithelial line cyst 
2) Implantation theory
Implantation of epithelium in the middle ear can cause cholesteotoma. Eg  blast injury, ear drum trauma /surgery
3) Metaplasia theory -Wendt 
Transformation of cubical epithelium in the middle ear to keratinised stratified squamous epithelium can occur. 
This is possible due to Secondary to chronic or recurrent OM 
4 Epithelial invasion theory 
Invasion of skin from meatal wall from marginal or attic perforation 

Pathology
Commonest site of origin is from the superior most aspect of the tympanic membrane due to a retraction pocket. Other sites are from the posterior aspect and within the middle ear it self. Expansion of the cholesteotoma leads to destruction of surrounding bone.

Reason for Bone erosion 

1 Mechanical 

 Pressure generated by cholesteatoma generating size with keratin and purulent debris

2 Bacterial endotoxins
3 Host granulation tissue products 
4 Substances from cholesteatoma itself, i.e. growth factors/ cytokines

5 Increased osteoclastic activity
6 Fig keratin FB reaction

Symptoms

Usual presentation is with ear discharge/ smelly-pseudomonas
There is usually a Hx of chronic childhood ear disease
Less commonly will present with infection/ pain/ mastoiditis- see complications of cholesteotoma below

Signs

Keratin
Debris
Attic Pocket
Attic Cholesteotoma

Attic disease/ middle ear-white- cholesteotoma

Attic polyp- cholesteotoma unless proven otherwise
Keratin build up within the middle ear-cholesteotoma

Complications

Abscess formation-Mastoiditis/ Intra Cranial/ Jugular thrombosis
Intra cranial extension of cholesteotoma
Facial Nerve involvement
Labyrinth damage- sensory hearing loss


Treatment

In Elderly patients this could be managed conservatively. This include suctioning of keratin and regular application of ointment such as Otocomb. The aim is to keep keratin build up to a minimum.
Surgery will involve mastoidectomy. This is to gain access to the middle ear space as well as to remove disease completely. Mastoid may be opened to the ear canal-Modified Radical Mastoidectomy, or canal may be left in tact. If canal is left intact, a second look is needed later on to rule out any residual cholesteotoma re growth.
Healthy modified radical mastoid cavity

large meatus- into a modified radical mastoid cavity

















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