Background 5 7 9 31 3 4 19 20 27 32 8 9 12 14 21 24 25 32 15 9 13 14 28 22 33 Materials and methods Sixty-two experts in the field of digestive endocrine tumors from 20 different countries attended the Consensus Conference. The attendees represented all medical branches involved in managing patients with gastroenteropancreatic NETs. They formed four working groups according to their specific clinical expertise: (1) pathology and genetics (11 participants, all listed as authors and G. Klöppel), (2) surgery (10 participants, including the coauthors H. Alhman and M. Falconi), (3) imaging and radiology (10 participants), (4) medicine and clinical pathology (31 participants, including the coauthors M. Caplin, W.W. de Herder, B. Erikssson, and B. Wiedenmann). The Conference was divided sequentially into eight sessions devoted to specific topics on an anatomical basis (gastric NET sessions 1–2, duodenal NET, pancreatic NET sessions 1–4, and poorly differentiated endocrine carcinomas). A working booklet with the ENETS guidelines and specific queries had been prepared in advance by the Organizing Committee. The work was organized such that, after a short case presentation in a plenary session, each working group gathered separately to discuss group-specific questions. Once agreement was reached within each group, consensus statements were discussed and approved or rejected by all participants gathered in the plenary session. This procedure was followed for all eight sessions. The TNM staging proposal was made by the Pathology and Genetics working group and amended and approved by the plenary session of the consensus conference. The grading system was discussed and defined by the Pathology and Genetics working group only. Results and discussion The consensus guidelines are reported elsewhere. Here, we report the TNM staging proposal for gastroenteropancreatic NETs of the foregut together with a grading system that may be relevant for the prognostic assessment by the pathologist. The foregut NETs were separated into gastric, duodenal (including ampulla and proximal jejunum), and pancreatic NETs, but were not distinguished according to specific functional activity, main tumor cell type, and specific genetic background. 1 2 3 29 Tumor 30 1 2 5 7 31 5 Nodes 11 1 2 3 Table 1 Proposal for a TNM classification and disease staging for gastric endocrine tumors TNM T—primary tumor  TX Primary tumor cannot be assessed  T0 No evidence of primary tumor  Tis In situ tumor/dysplasia (<0.5 mm)  T1 Tumor invades lamina propria or submucosa and ≤1 cm  T2 Tumor invades muscularis propria or subserosa or >1 cm  T3 Tumor penetrates serosa  T4 Tumor invades adjacent structures  For any T, add (m) for multiple tumors N—regional lymph nodes  NX Regional lymph nodes cannot be assessed  N0 No regional lymph node metastasis  N1 Regional lymph node metastasis M—distant metastasis  MX Distant metastasis cannot be assessed  M0 No distant metastases a Distant metastasis Stage  Disease stages   Stage 0 Tis N0 M0   Stage I T1 N0 M0   Stage IIa T2 N0 M0    IIb T3 N0 M0   Stage IIIa T4 N0 M0    IIIb Any T N1 M0   Stage IV Any T Any N M1 a 29 Table 2 Proposal for a TNM classification and disease staging for endocrine tumors of the duodenum/ampulla/proximal jejunum TNM T—primary tumor  TX Primary tumor cannot be assessed  T0 No evidence of primary tumor  T1 a  T2 Tumor invades muscularis propria or size >1 cm  T3 Tumor invades pancreas or retroperitoneum  T4 Tumor invades peritoneum or other organs  For any T, add (m) for multiple tumors N—regional lymph nodes  NX Regional lymph nodes cannot be assessed  N0 No regional lymph node metastasis  N1 Regional lymph node metastasis M—distant metastases  MX Distant metastasis cannot be assessed  M0 No distant metastases b Distant metastasis Stage  Disease stages   Stage I T1 N0 M0   Stage IIa T2 N0 M0     IIb T3 N0 M0   Stage IIIa T4 N0 M0     IIIb Any T N1 M0   Stage IV Any T Any N M1 a b 29 Table 3 Proposal for a TNM classification and disease staging for endocrine tumors of the pancreas TNM T—primary tumor  TX Primary tumor cannot be assessed  T0 No evidence of primary tumor  T1 Tumor limited to the pancreas and size <2 cm  T2 Tumor limited to the pancreas and size 2–4 cm  T3 Tumor limited to the pancreas and size >4 cm or invading duodenum or bile duct  T4 Tumor invading adjacent organs (stomach, spleen, colon, adrenal gland) or the wall of large vessels (celiac axis or superior mesenteric artery)  For any T, add (m) for multiple tumors N—regional lymph nodes  NX Regional lymph node cannot be assessed  N0 No regional lymph node metastasis  N1 Regional lymph node metastasis M—distant metastases  MX Distant metastasis cannot be assessed  M0 No distant metastases a Distant metastasis Stage  Disease stages   Stage I T1 N0 M0   Stage IIa T2 N0 M0    IIb T3 N0 M0   Stage IIIa T4 N0 M0    IIIb Any T N1 M0   Stage IV Any T Any N M1 a 29 Distant metastasis 6 20 29 Staging 4 Grading 10 25 32 16 18 22 23 4 2 2 2 Table 4 Grading proposal for foregut (neuro)endocrine tumors Grade a b G1 <2 ≤2 G2 2–20 3–20 G3 >20 >20 a 2 b 26 5 7 31 Mitotic count and Ki-67 index Concluding remarks 16 17 22 23