Case of the Week
Section Editors: Matylda Machnowska1 and Anvita Pauranik2
1University of Toronto, Toronto, Ontario, Canada
2BC Children's Hospital, University of British Columbia, Vancouver, British Columbia, Canada
Sign up to receive an email alert when a new Case of the Week is posted.
October 22, 2015
Labyrinthitis Ossificans (Ossifying Stage)
- Background:
- Pathologic ossification of the spaces in the membranous labyrinth as a response to a destructive process such as meningitis, vascular occlusion, autoimmune processes or trauma
- In the acute stage, a purulent/serofibrinous exudate appears within the perilymphatic spaces.
- During the fibrous stage (2 weeks – 2 months), fibroblastic proliferation and fibrosis occurs.
- In the late or ossifying stage, osteogenesis and osteoid deposition occur. The most common ossified area is the basal turn of the cochlea.
- Clinical Presentation: Unilateral or bilateral severe-to-profound hearing loss
- Key Diagnostic Features:
- Acute stage: Inner ear enhancement on MRI; often normal CT
- Fibrous stage: Loss of fluid signal intensity on heavily T2-weighted MRI; normal CT
- Ossifying stage: Cochlea and/or vestibular system are replaced by bone attenuation on CT.
- DDx (clinical):
- Michel deformity
- Cochlear otosclerosis
- Labyrinthine schwannoma
- Treatment Options: Cochlear implant surgery in selected cases. Specific surgical considerations are necessary in the ossifying stage; therefore, presurgical imaging characterization is essential.
Current Issue
Case Collections
