Otosclerosis associated with type B-1 inner ear malformation.

Malformations of bony inner ear are rare anomalies occurring in approximately 20% of patients with congenital sensorineural hearing loss. Conductive hearing loss is usually associated with abnormalities of the external and middle ear. Recent reports of patients with lateral semicircular canal malformations indicate inner ear malformations to be associated with sensorineural or conductive hearing loss. Differential diagnosis of conductive hearing loss should include otosclerosis, isolated ossicular deformities, inner ear anomalies or a combination of these. In this report, a case is described with right vestibule-lateral semicircular canal dysplasia presenting at our centre with bilateral otosclerosis.