Dural ectasia as a cause of widening of the internal auditory canals in neurofibromatosis.

Patients with neurofibromatosis have an increased incidence of acoustic neuroma, which is often bilateral. We present three patients with neurofibromatosis and enlarged internal auditory canals secondary to dural ectasia, without associated acoustic neuromata. Air CT cisternography and Metrizamide CT cisternography was needed in differentiating dural ectasia from acoustic neuroma in two patients.