CHOLESTEATOMA - A DISEASE OF ABNORMAL KERATINOCYTE PROLIFERATION INDUCED BY IMMUNE CELLS

Cholesteatoma of the middle ear consists of keratinising squamous epithelium in the middle ear cavity. Many points of the pathogenesis of cholesteatoma seem to be related to immune cell infiltrates in stroma and to epithelial cell migration and proliferation. In our study we found that the vast majority of cells infiltrating the stroma consisted of T-cells and macrophages, showing an immunologically activated state. Furthermore, the cholesteatoma epithelium showed an enhanced simultaneous expression of keratine-16 and Ki-67 positive cells. This expression was accompanied by the over-expression of transforming growth factor (TGF)-alpha, and its receptor, epidermal growth factor receptor (EGF-R) and interleukin-1, suggesting that the proliferation of keratinocytes could be stimulated in an autocrine manner. Finally, we conclude that the presence of immunologically activated immune cells in the stroma may be responsible for keratinocyte dysregulation in cholesteatoma epithelium.