The spatial organisation of keratinocytes in acquired middle ear cholesteatoma resembles that of external auditory canal skin and pars flaccida.

A scanning electron microscopic study of acquired middle ear cholesteatoma was undertaken in order to compare morphological findings with those of keratinising squamous epithelium of the tympanic membrane and external auditory meatus. Analysis of results confirms a highly ordered vertical architecture, with cell stacking, in the stratum corneum of cholesteatoma, similar to that found in the skin of the deep external auditory meatus and the pars flaccida of the tympanic membrane. These findings support the notion that acquired cholesteatoma originates by immigration of epithelium from the pars flaccida and external meatus rather than by metaplasia of middle ear mucosa.