[Genetic factors in middle ear cholesteatoma]

A constitutionally narrow Eustachian tube inhibits development of the middle ear. The mastoid process often remains completely non-pneumatised. Furthermore embryonic connective tissue fills the epitympanum, and rarely the entire middle ear. There is no doubt of its susceptibility to infection during childhood. This favours the development of chronic inflammatory granulation tissue, and induces a typical papillary downgrowth of the epidermis of the tympanic membrane. According to this hypothesis a cholesteatoma usually develops from the epitympanum and only exceptionally from the meso- or hypotympanum.