Updates of pancreatic neuroendocrine neoplasm in the 2017 World Health Organization classification

The new 2017 World Health Organization (WHO) classification of pancreatic neuroendocrine neoplasms (PanNEN) modifies the previous 2010 version with new grading and staging systems to provide a better prognostic stratification and therapeutic guidance. The discovery of heterogeneity in WHO 2010 G3 category leads to the introduction of the new ‘well‐differentiated neuroendocrine tumor G3’ entity, which is distinct from the poorly‐differentiated pancreatic neuroendocrine carcinoma (PanNEC). The latest findings from molecular studies of PanNEN allow us to have a better understanding of respective biology of PanNET and PanNEC. This review aims at highlighting refinements in the 2017 classification and discusses some of the molecular updates in PanNEN.