Mucosubstance histochemistry and pathogenesis of acquired cholesteatoma

Mucosubstance histochemical study of 33 cholesteatoma tissues was performed to clarify the distribution and character of mucin in the perimatrix. Mean density of glandular cysts was 0.18 per mm². Mean frequency of ruptured cysts was 0.16 per cyst. Glandular cysts as well as hallow spaces in the perimatrix were filled with sulfomucin and sialomucin. Fragments of mucin were found in some macrophages and multinucleated giant cells. Since phagocytosis is host defenses attempt, the process indicates that mucin in the perimatrix is a cause of inflammation. Sialomucin infiltrated in the subepidermis where the epidermis formed papillary proliferation without an apparent sign of inflammation. Six glandular cysts were found in the matrix and the debris. They may have been eliminated from the perimatrix as a sequel to cholesteatoma growth. These findings suggest that embedded mucosa in the perimatrix may play a crucial role in pathogenesis of acquired cholesteatoma.