The clinical features and pathogenesis of myringitis granulosa.

Myringitis granulosa is not a rare pathologic condition of the tympanic membrane. However, the condition can be misdiagnosed as chronic suppurative otitis media, since intermittent purulent discharge is the commonest symptom in both disorders. Although the clinical features of myringitis granulosa have been well described by several authors, its pathogenesis is still obscure. In this study, 40 cases of myringitis granulosa were examined in detail to clarify the clinical features and the pathogenesis present. No drum perforations, no hearing impairments and normal X-ray findings indicated that myringitis granulosa had no relation to chronic suppurative otitis media. The other areas of the affected tympanic membrane, except for the site of granulation, showed such pathologic conditions as atrophy, clouding and calcifications. In these pathologic tympanic membranes, epithelial migration was disturbed to a high degree. We suggest that the granulation process on the tympanic membrane should be divided into two stages: (1) injury reaching the lamina propria of the tympanic membrane; and (2) disturbed epithelization of the tympanic membrane. The disturbance of epithelial migration of the tympanic membrane occurs with both stages.