The problem of middle ear cholesteatoma: etiology, genesis and pathobiology. A review.

This review provides an overview of the problem of middle ear cholesteatoma, and encompasses the following areas: the definition, the light and ultramicroscopic structure, the etiology, the pathogenesis (with special emphasis on the congenital or "embryonic rest" theory, immigration, invagination and papillary ingrowth, traumatic or iatrogenic implantation and metaplastic origin), and finally the pathology of cholesteatoma including bone erosion. An attempt is made to distill the actual and leading thoughts concerning this intriguing entity.