Original Article

Virchows Archiv

, Volume 451, Issue 4, pp 757-762

First online:

Open Access This content is freely available online to anyone, anywhere at any time.

TNM staging of midgut and hindgut (neuro) endocrine tumors: a consensus proposal including a grading system

  • G. RindiAffiliated withDepartment of Pathology, University of ParmaDipartimento di Patologia e Medicina di Laboratorio, Sezione di Anatomia Patologica, Università di Parma Email author 
  • , G. KlöppelAffiliated withDepartment of Pathology, University of Kiel
  • , A. CouvelardAffiliated withDepartment of Pathology, Hôpital Beaujon
  • , P. KomminothAffiliated withDepartment of Pathology, Stadspital Triemli
  • , M. KörnerAffiliated withDepartment of Pathology, University of Bern
  • , J. M. LopesAffiliated withDepartment of Pathology, Porto Medical School & IPATIMUP, University of Porto
  • , A.-M. McNicolAffiliated withDepartment of Pathology, Glasgow Royal Infirmary
  • , O. NilssonAffiliated withDepartment of Pathology, Gothenborg University
  • , A. PerrenAffiliated withDepartment of Pathology, Klinikum rechts der Isar
    • , A. ScarpaAffiliated withDepartment of Pathology, University of Verona
    • , J.-Y. ScoazecAffiliated withDepartment of Pathology, University of Lyon
    • , B. WiedenmannAffiliated withDepartment of Internal Medicine, Campus Virchow Klinikum


Criteria for the staging and grading of neuroendocrine tumors (NETs) of midgut and hindgut origin were established at the second Consensus Conference in Frascati (Rome) organized by the European Neuroendocrine Tumor Society (ENETS). The proposed tumor–node–metastasis (TNM) classifications are based on the recently published ENETS Guidelines for the Diagnosis and Treatment of gastroenteropancreatic NETs and follow our previous proposal for foregut tumors. The new TNM classifications for NETs of the ileum, appendix, colon, and rectum, and the grading system were designed, discussed, and consensually approved by all conference participants. These proposals need to be validated and are meant to help clinicians in the stratification, treatment and follow-up of patients.


Neuroendocrine tumors Ileum Appendix Colon Rectum Staging TNM Grading Mitotic index Ki-67 index