Abstract:

Neuroendocrine neoplasm (NEN)is a group of heterogeneous tumors originated from the peptidergic neurons and neuroendocrine cells. A revised system of classification, nomenclature and grading of NEN was proposed by the fourth edition of “World Health Organization classification of tumours of the digestive system”in 2010. It apparently contributes to unify the method of classification, put an end of the confusion in nomenclature, standardize the grading system and predict the outcomes more accurately. With the combination of the results by immunohistochemical studies, pathologists should be in accordance with the requirements to make a diagnosis of NEN with accurate classification, grading and the pathological parameters essential to staging. Recently, new advances in NEN study put forward a new view in the classification and grading system that will lead to the updates of the diagnostic system after further studies on a large scale of samples.

Key words: Gastroenteropancreatic neuroendocrine neoplasm, Pathological diagnosis, Immunohistochemistry