Role of retraction pockets in cholesteatoma formation.

Temporal bones were obtained from 100 routine cases at post mortem who died of causes other than otological. The tympanic membranes were examined under the operating microscope and retraction pockets were seen and photographed in 12 cases. Radiological examination of these 12 mastoid bones showed a sclerotic mastoid in 8 cases. On serial histopathological examination of the temporal bones there was evidence of old or recent chronic otitis media in each case. In 3 cases a sac with a narrow neck leading to the retraction pocket was seen. In 2 cases squamous epithelial 'pearls' in close proximity to the retraction pockets were seen. The significance of these findings in the pathogenesis of retraction pockets and cholesteatoma is discussed.