World Health Organization 2016 Classification of Central Nervous System Tumors

The recent update of the World Health Organization (WHO) classification of tumors of the central nervous system represents a paradigm shift. Previous iterations of the classification relied on morphologic features for classification. In the 2016 update, the definitions of specific neoplastic entities tumors now include precise molecularly defined entities. This article discusses this paradigm shift and focuses on the refinements in classification criteria, relations to previous editions, and their implication to neuropathology and neuro-oncology practice. The authors distinguish the criteria that were used to determine why molecular changes were included.