Duplicated internal auditory canal with inner ear malformation: Case report and literature review.

Internal auditory canal anomalies are rare. Narrow internal auditory canal is believed to occur as a result of aplasia or hypoplasia of the vestibulocochlear nerve. Narrow duplication of the internal auditory canal is considered to be very rare. Narrow duplication of the internal auditory canal with inner ear malformation has been reported in only 3 cases. We present 2 cases of narrow duplication of the internal auditory canal with inner ear malformation. The first case had inner ear malformation on only one side and the second case had inner ear malformation on both sides. The embryogenesis may be different between internal auditory canal and inner ear.