[New concepts of the course of cholesteatoma from the immunohistological study of 96 samples].

The immunohistological characteristics of retraction pockets, cholesteatoma matrix and granulomatous tissue have been compared. Langerhans cells, epidemic folds and sub-epithelial tissue were labelled with specific markers (HLA II, adhesion receptors, KI 67). The junction between epidermis and sub-epithelial tissue of middle ear mucosa appeared as the most inflammatory area, displaying characteristics of delayed type hypersensitivity phenomenon. CD1+ Langerhans cells appear to express class II molecules only in the vicinity of polymorphonuclear infiltrates. Epidemic proliferation seems to able place mainly in the deepest recesses of the epidermis.