Electron microscope study of bone lesion in cholesteatoma otitis

Zusammenfassung

Die elektronenmikroskopische Untersuchung von Knochenbiopsien bei Cholesteatomoperationen zeigt Veränderungen der kollagenen Knochenmatrix sowie eine ausgedehnte Degeneration von Knochenzellen. Dabei findet sich die Oberfläche des veränderten Knochens in direktem Kontakt mit dem subepithelialen Bindegewebe oder mit Granulationen, nicht aber mit dem Plattenepithel selbst. Die Untersuchungen zeigen, daß entzündliche Prozesse in den dem Knochen benachbarten Bindegewebslagen vorwiegend für die Knochenzerstörung bei Cholesteatom verantwortlich sind.

Summary

Biopsy specimens were obtained at ear surgery of patients with cholesteatoma otitis and were studied by electron microscopy. The osseous tissue decalcified in EDTA demonstrated degradation of collagen matrix as well as extensive degeneration of bone cells. The surface of the eroded bone was found to be in direct contact with the subepithelial connective tissue or the granulation, but not with the keratinizing squamous epithelium of matrix. These results indicate that the bone destruction by cholesteatoma is of non-osteoclastic type and lend support to the view that the keratinizing squamous epithelium do not participate in bone destruction. On the ultrastructural basis, the inflammatory process in the soft tissue adjacent to bone and extensive degeneration of bone cells are considered as cardinal factors for bone destruction in this disease.