Ectopic choroid plexus within a juvenile arachnoid cyst of the cerebellopontine angle: Cause of cyst formation or reason of cyst growth

The unusual and ra re case of a 6-year-old boy is reported who presented wi th an arachnoid cyst located in the cerebellopontine angle incorporating an ectopic piece of choroid plexus tissue, A microneurosurgical cyst wail res ection was performed and the plexus tissue identified and removed, The rare occurrence of ectopic choroid plexus tissue within cysts of the CNS is dis cussed. Copyright (C) 2000 S. Karger AG, Basel.