<prompt> Which is the most common childhood CNS tumor metastasize outside brainEpendymomaGlioblastoma multiformeChoroid plexus tumorMedulloblastoma  <response>: Medulloblastoma is the childhood brain tumor that most commonly metastasizes extraneuronally.- Nelson Also know There are age-related differences in primary location of tumor. Most common brain tumor in children 1 yr of age -- Choroid plexus tumors Choroid plexus papilloma and choroid plexus carcinoma MC primary brain tumor in adults -- Glioblastoma Multiforme Most malignant primary brain tumor in adults- Glioblastoma Multiforme Ref : Nelson 18e p2136 