Histopathologic changes of the tympanic membrane in acute and secretory otitis media.

The histopathologic changes observed in 40 normal and inflamed temporal bones of infants and children are reported. The tympanic membranes of patients with acute and secretory otitis media underwent considerable swelling compared to those of normal controls. Tympanic membranes with acute otitis media were thicker than those with secretory otitis media, but the difference was not statistically significant. The epithelial layer showed an increase in the number of cell layers. The lamina propria demonstrated the most significant changes of all layers with a marked swelling due to edema, engorged blood vessels, and inflammatory cell infiltration. Increased numbers of distended capillaries were present, predominantly in the subepithelial connective tissue layer, while infiltration of inflammatory cells was mainly in the submucosal connective tissue layer. By contrast, the involvement of the mucosal layer was modest and was composed of cuboidal cells, except for small islands of metaplastic mucosa with mucus production occasionally encountered in specimens with secretory otitis media.