Delayed ultrastructural radiation induced changes in the human mesotympanic middle ear mucosa.

The irradiation-induced changes in the middle ear mucosa of six patients were described and discussed. The epithelium showed marked reduction of the cytoplasmic mass, variable degrees of ciliary loss and widening of the intercellular spaces with disruption of some of the maculae adherentes. The connective tissue stroma showed increased production of collagenous fibrous tissue and increased number of synthetically active fibroblasts. New gland formation has been observed and the glands exhibited reduced activity. The endothelial cells of some blood capillaries were swollen and the basal lamina was duplicated. The lumina of other capillaries were completely obliterated and replaced by a cord of fibrous tissue.