Cerebellopontine angle meningioma causing asymptomatic syringomyelia--case report.

A 36-year-old female was admitted with a 3-month history of headache and gait disturbance. Magnetic resonance imaging demonstrated a large tumor in the right cerebellopontine angle and syringomyelia in the upper cervical cord associated with caudal displacement of the cerebellar tonsil. Complete removal of the tumor resulted in disappearance of these associated conditions. Herniation of the cerebellar tonsil and distortion of the brain stem had probably caused disturbance of cerebrospinal fluid flow, which combined with obstruction of the spinal canal, caused the syrinx.