Choroid plexus papilloma, light micrograph. Choroid plexus tumours comprise爈ess than 1% of all brain tumours. Almost?0% of cases occur in children爉aking up?% to 4% of pediatric brain tumours. The most common location is爈ateral ventricles. Given their location, the presenting symptoms and signs are related to爃ydrocephalus燼nd爄ncreased intracranial pressure. Choroid plexus papillomas are燾ircumscribed, papillary masses燾onsisting of爌seudostratified epithelial cells lining fibrovascular cores. Note the orderly arrangement of epithelial cells around fibrovascular cores. Cytologic atypia is absent and mitotic activity is not increased. Choroid plexus papillomas are low-grade tumours (WHO Grade 1) and cured by total resection (100% 5-yr survival).