Gastric Neuroendocrine Hyperplasia, Dysplasia and Neoplasia (Carcinoid Tumors)
Grading / Staging
Proposed grading scale based on proliferation
| Grade | Mitotic count per 10 hpf | % of cells Ki67+ |
|---|---|---|
| G1 | <2 | ≤2 |
| G2 | 2-20 | 3-20 |
| G3 | >20 | >20 |
- Mitotic counts based on 50 hpf
- Ki67 % based on 500-2000 cells
- If discrepant, use higher grade
- Scale proposed by European Neuroendocrine Society (ENETS)
- Carcinoids / neuroendocrine tumors may be G1 or G2
- G3 is definitional for high grade neuroendocrine carcinoma
- Progression from G1/2 to G3 is quite rare
- G3 appears to be a separate process
Grading/Staging References
- Rindi G, Klöppel G, Couvelard A, Komminoth P, Körner M, Lopes JM, McNicol AM, Nilsson O, Perren A, Scarpa A, Scoazec JY, Wiedenmann B. TNM staging of midgut and hindgut (neuro) endocrine tumors: a consensus proposal including a grading system. Virchows Arch. 2007 Oct;451(4):757-62.
- Rindi G, Klöppel G, Alhman H, Caplin M, Couvelard A, de Herder WW, Erikssson B, Falchetti A, Falconi M, Komminoth P, Körner M, Lopes JM, McNicol AM, Nilsson O, Perren A, Scarpa A, Scoazec JY, Wiedenmann B; and all other Frascati Consensus Conference participants; European Neuroendocrine Tumor Society (ENETS). TNM staging of foregut (neuro)endocrine tumors: a consensus proposal including a grading system. Virchows Arch. 2006 Oct;449(4):395-401.
Correlation of grade with stage
| Grade | Approx incidence of node mets | Approx incidence of distant mets |
|---|---|---|
| G1 | 5% | 2.5% |
| G2 | 30% | 10% |
| G3 | 70% | 70% |
Staging
- GI neuroendocrine tumors should be staged according to AJCC TNM 7th edition
