ELECTRON MICROSCOPIC STUDY OF THE INCUS AND MALLEUS IN CHRONIC SUPPURATIVE OTITIS MEDIA WITH CHOLESTEATOMA

Abstract

Chronic suppurative otitis media can be divided into safe type (mucosal type= tubo-tympanic type) and unsafe type (bone eroding type= attico-antral type). The latter is further sub-divided into Cholesteatomatous type and non-cholesteatomatous type. Definition of cholesteatoma:

It is a pathological entity characterized by bone-eroding, skin -lined cavity filled with concentric layers of desquamated epithelium and exfoliated keratin in the middle ear or other pneumatized areas of temporal bone. Although the term keratoma describes the condition better, the term cholesteatoma is in general use. Classification of cholesteatoma according to its pathogenesis can be divided into three main types: congenital cholesteatoma, primary acquired cholesteatoma and secondary acquired cholesteatoma. Another classification of cholesteatoma, based on the anatomical site of the

i disease with reference to the tympanic membrane could divide cholesteatoma into:

pars flaccida cholesteatoma, pars tensa cholesteatoma and occult cholesteatoma.

Classification of cholesteatoma according to its site and etiology: attic cholesteatoma, sinus cholesteatoma, tensa retraction cholesteatoma, ear canal cholesteatoma, post-traumatic cholesteatoma, congenital cholesteatoma (occult), residual cholesteatoma, recurrent cholesteatoma and iatrogenic cholesteatoma. Pathogenesis of congenital cholesteatoma was referred to epithelial rest of embryonal origin while the pathogenesis of acquired cholesteatoma was referred to