[MALT and the Epithelium of the Middle Ear Mucosa. Morphological Studies].

Introduction: The mucosa of the middle ear and the Eustachian Tube changes in different ways when faced with recurrent episodes of inflammation. It thereby adapts to these new stimuli and insults from the environment. One of these changes is the development of MALT (mucosa associated lymphoid tissue). Another adaptation is an alteration of the epithelium. It was therefore the purpose of this study to look for a connection between the occurrence of these changes.

Material And Methods: 90 sections of temporal bones were examined under the light microscope and the incidence of MALT and nature of the epithelium found were compared.

Results: Particularly in the middle ear, we demonstrated that in cases where MALT was found within the mucosa, columnar epithelium was frequently found in locations where it is typically rare. Squamous epithelium was in many cases replaced by cuboidal epithelium.

Discussion: We demonstrated that the mucosa of the middle ear changed its morphology towards the characteristics typically found in the upper respiratory tract in cases where MALT had developed as subepithelial lymphoid follicles. It can therefore be concluded that both changes represent the mucosa's reaction to recurrent or chronic inflammation.