Experimental studies of cholesteatomas. In vivo studies on epithelial-mesenchymal interaction and bone resorption in the immunodeficient "nude" mouse.

A model for studying different aspects of human cholesteatomas in vivo and in the immunodeficient "nude" mouse is described. Epithelial-mesenchymal interaction was studied in human cholesteatoma membranes, transplanted to the flank region. Findings of cystic lesions lined by stratified keratinizing epithelium were frequent, and the connective tissue reaction was weak. Furthermore, human cholesteatoma membranes were transplanted into the middle ear cavity of 'nude' mice. After 21-28 days, bone resorption was found in the labyrinthine capsule, but not always with signs of inflammation.