2007 Volume 17 Issue 5 Pages 671-676
Wegener's granulomatosis (WG) was first described as a disease independent of polyarteritis nodosa by Dr. Wegener in 1939. Its main pathological features are necrotizing granuloma and vasculitis of the upper airway, lower airway, and kidney. However WG can also involve the temporal bone because it is a systemic autoimmune disease. There were few reports showing the temporal bone pathological findings, and the mechanism of sensorineural hearing loss has not yet been elucidated. We described the mechanism of hearing loss on the basis of temporal bone pathological findings.
The patient was a 74-year-old woman whose first symptom was nasal discharge with blood. She was diagnosed of WG and administered with cyclophosphamide and steroid, and subjected to radiation therapy. However her hearing loss deteriorated, and finally she died of pneumonia. Temporal bone pathological findings revealed almost total loss of osteoblasts in the both cochlear and vestibular labyrinthine capsules, resolution of the vestibular bony labyrinth, and infiltration of inflammatory cells into the vestibular labyrinth. We speculated the following mechanism. Deposition of autoimmune complexes in the vessel walls of the labyrinthine capsule caused thickening of the vessel walls, and blood flow was disturbed. This led the labyrinthine capsule to necrosis with osteoblast defluxion. Finally, the bony labyrinth was resolved, and inflammation occured in the inner ear. This was thought to be one of the mechanisms of sensorineural hearing loss associated with WG.
