Glial Tumors

Abstract Glial tumors comprise the majority of primary intra-axial intracranial tumors. Since its introduction in 2016, the revised fourth edition of the World Health Organization (WHO) classification of central nervous system tumors has changed the diagnostic and therapeutic approach in glial tumors (WHO Classification of Tumours of the Central Nervous System [revised fourth edition]; Lyon, France: IARC; 2016). Diffuse gliomas (WHO grades II–IV) are now molecularly stratified based on isocitrate dehydrogenase 1 or 2 mutation status and classified according to 1p/19q codeletion status into astrocytic or oligodendroglial type. Updates now occur faster than new editions of the WHO classification can be prepared, so updates are being issued by way of journal articles from a Consortium to Inform Molecular and Practical Approaches to CNS Tumor Taxonomy (Brain Pathol 2019;29(4):469–472).