A contribution to the pathogenesis of cholesteatoma. A histochemical and ultrastructural study.

In a histochemical and ultrastructural study the pathogenesis of cholesteatoma ostitis is analysed on human tissue. In the subepithelial layer there is evidence of an inflammatory reaction leading to proliferation of granulation tissue with bony invasion. Bony destruction is initiated by osteocytic osteolysis. In the case of cholesteatoma there is a combined action of extraosseous and osseous lysosomal enzymes. The pathological changes of the fibrillar elements suggest that the self-perpetuation of degeneration is maintained by a disturbance of fibrillogenesis. The causal pathogenesis of cholesteatoma formation is discussed as a function of a disturbance between cellular activity, extracellular matrix, and cellular surface.