title: [Neuroendocrine neoplasia of the stomach : What is new?]
abstract: BACKGROUND
  Neuroendocrine Neoplasms are classified according to the new WHO classification in (1.) well differentiated neuroendocrine tumors G1 (NET G1, Ki67 ≤ 2 or mitosis count <2) and (2.) well differentiated neuroendocrine tumors G2 (NET G2, Ki67 3-20 or mitosis count 2-20) and (3.) poorly differentiated neuroendocrine carcinomas G3 (NEC G3, Ki67 > 20 or mitosis count >20).
  
  
  METHODS
  In this study 310 NENs of the Ludwig-Maximilians-University in Munich were reevaluated according to the new WHO classification.
  
  
  RESULTS
  7% of the analyzed NENs were presented as neoplasias of the stomach. In NENs of the stomach three distinct subtypes are recognized: (1) type 1 associated with autoimmune chronic atrophic gastritis (2) type 2, associated with multiple endocrine neoplasia (MEN1) and Zollinger-Ellison Syndrom; and (3) type 3, sporadic tumors.
  
  
  CONCLUSIONS
  Precursor lesions (i. e. hyperplasia of the ECL cells) are found in patients with hypergastrinaemia (type 1 and 2). This article should provide insights into the diagnosis of NENs of the stomach with emphasis on the new international standard.
authors.affiliation: Pathologisches Institut, Ludwig-Maximilians-Universität (LMU), Thalkirchnerstr. 36, 80337, München, Deutschland. Thomas.Knoesel@med.uni-muenchen.de.
authors.forename: T
authors.initials: T
authors.lastname: Knösel
authors.affiliation: Pathologisches Institut, Ludwig-Maximilians-Universität (LMU), Thalkirchnerstr. 36, 80337, München, Deutschland.
authors.forename: C
authors.initials: C
authors.lastname: Reiter
authors.affiliation: Tumorregister München (TRM) des Tumorzentrums München (TZM), Institut für Medizinische Informationsverarbeitung, Biometrie und Epidemiologie (IBE), Ludwig-Maximilians-Universität (LMU), München, Deutschland.
authors.forename: G
authors.initials: G
authors.lastname: Schubert-Fritschle
authors.affiliation: Abteilung für Allgemein-, Viszeral- und Gefäßchirurgie, Friedrich-Schiller-Universität, Jena, Deutschland.
authors.forename: A
authors.initials: A
authors.lastname: Altendorf-Hofmann
authors.affiliation: Pathologisches Institut, Ludwig-Maximilians-Universität (LMU), Thalkirchnerstr. 36, 80337, München, Deutschland.
authors.forename: T
authors.initials: T
authors.lastname: Kirchner
mesh_terms: D001327:Autoimmune Diseases / Q000150:complications / Q000175:diagnosis; D002454:Cell Differentiation; D005756:Gastritis / Q000150:complications / Q000175:diagnosis; D006801:Humans; D006965:Hyperplasia / Q000473:pathology; D019394:Ki-67 Antigen / Q000235:genetics; D008938:Mitosis; D018761:Multiple Endocrine Neoplasia Type 1 / Q000150:complications / Q000175:diagnosis; D018358:Neuroendocrine Tumors / Q000145:classification*; D013274:Stomach Neoplasms / Q000145:classification*; D014944:World Health Organization; D015043:Zollinger-Ellison Syndrome / Q000150:complications / Q000175:diagnosis
chemical_list: D019394:Ki-67 Antigen; C000628856:MKI67 protein, human
keywords: Classification; ECL cells; Neuroendocrine neoplasms; Precursors; Prognosis