The New World Health Organization Classification for Pancreatic Neuroendocrine Neoplasia

Based on the 2010 version, the 2017 World Health Organization (WHO 2017) classification is for pancreatic neuroendocrine neoplasms (PanNEN). The WHO 2017 classification introduces the novel well-differentiated neuroendocrine tumor of high grade (NET G3). A sharp distinction between NET and poorly differentiated neuroendocrine carcinoma (NEC) is emphasized to highlight substantial biological differences. Further changes comprise the definition of mixed neuroendocrine non-neuroendocrine neoplasm (MiNEN), to accommodate all grades of both neoplasm components, and the abolition of preneoplastic lesions given their rarity in the pancreas. The 2017 American Joint Cancer Committee classification (AJCC 2017) adopts such a classification for all digestive sites.