Pathology and pathogenesis of tympanic membrane retraction.

Temporal bones without evidence of otitis media, as well as temporal bones with various types of otitis media, were examined for the presence of retractions of the tympanic membrane and their related histopathologic progression to the formation of cholesteatoma. Retractions were not present in non-otitis media, purulent, or mucoid otitis media. Retractions were observed in 2.1% of temporal bones with serous otitis media and 19.5% of temporal bones with chronic otitis media. All temporal bones with retractions demonstrated evidence of current or previous otitis media. Histopathologic changes of the middle ear cleft were associated with the type and degree of retraction. This study supports the continuum theory according to which otitis media with effusion eventually leads to a variety of sequelae and/or to chronic otitis media. The tympanic membrane appears to follow progressive changes, from simple retraction to retraction pockets and finally to cholesteatoma.