[Histological and ultrastructural aspects of oto-mastoid cholesteatoma in children].

Cholesteatomas were intraoperatively removed from subjects under 14 years of age presenting widespread cholesteatoma with bone erosion. The samples were studied under light and transmission electron microscopy in order to consider the features of inflammation and bone erosion. The results showed that the perimatrix of cholesteatoma in children is rich in mononuclear inflammatory elements and generally presents the features of chronic, as well as acute, inflammation. The perimatrix infiltrates and erodes the surrounding bone. Next to the resorption areas many areas were observed having new bone the surface of which is lined with osteoblasts. The new bone formation activity is marked in these cases of childhood cholesteatoma and appears to be an attempt at spontaneous repair which is thwarted by the persistence of inflammation.