[Expression of calgranulin A and B in middle ear cholesteatoma]

Cholesteatoma epithelium is characterised by a keratinocyte dysregulation with a hyperproliferative growth and altered differentiation. Keratinocytes with a reduced turnover time show an increase of calcium binding proteins like calgranulin A and B. These proteins are highly linked with the modulation of cell growth and differentiation. The expression of calgranulin A and B was studied immunohistochemically using the monoclonal antibody F12 on cryosections of cholesteatoma biopsies. Normal skin served as control. The staining in normal skin was confined to the highly proliferative activated follicular keratinocytes, whereas most cholesteatomas showed a staining of all cell layers of the epithelium. Our findings show that the keratinocyte dysregulation of the cholesteatoma epithelium is reflected by variations of the expression of calcium binding proteins.