Choroid plexus carcinoma, light micrograph. Choroid plexus tumours comprise爈ess than 1% of all brain tumours. Almost?0% of cases occur in children爉aking up 2% to 4% of pediatric brain tumours. The most common location is爈ateral ventricles. This choroid plexus carcinoma (WHO Grade III) shows爌apillary and solid growth patterns. Cytologic atypia is evident and mitotic activity was increased to 10 mitoses/10 HPF. The treatment consists of surgical resection followed by chemotherapy and/or radiation. The爌rognosis is poor爓ith a?-yr survival rate of only around 40%.