Temporal Bone Histopathology of Atypical Cogan Syndrome

Cogan's syndrome is a rare disorder first clinically defined in 1945, characterized by nonsyphilitic interstitial keratitis and progressive audiovestibular symptoms. Later, patients with audiovestibular dysfunction and various types of inflammatory eye disease were classified as having atypical Cogan's syndrome. The etiology and pathogenesis of Cogan's syndrome remain largely unknown. Here, we report a case of atypical Cogan's syndrome with a histological assessment of the temporal bone during the acute disease period. Temporal bone histology was compared to age- and gender-matched normal control, and our findings revealed endolymphatic hydrops and degenerative changes in various parts of the inner ear. Laryngoscope, 134:5135-5138, 2024.