Table 3.
WHO classification of NETs of pancreas, GI tract, and lung.
| 2017, Pancreas [46] |
2010, GI tract [32] |
2015, Lung [33] |
|||||||
|---|---|---|---|---|---|---|---|---|---|
| Classification | Differentiation | Ki-67 index (%) |
Mitotic count (/10 HPF) |
Classification | Ki-67 index (%) |
Mitotic count (/10 HPF) |
Classification | Mitotic count (/10 HPF) |
Necrosis |
| NET G1 | Well | < 3 | < 2 | NET G1 | ≤ 2 | < 2 | Typical carcinoid | < 2 | Absence |
| NET G2 | Well | 3–20 | 2–20 | NET G2 | 3–20 | 2–20 | Atypical carcinoid | 2–10 | Absence or punctiform |
| NET G3 | Well | > 20 | > 20 | NEC | > 20 | > 20 | NEC, large cell type |
> 10 | Large |
| NEC (G3) | Poor (large cell or small cell type) |
> 20 | > 20 | NEC, small cell type |
> 10 | Large | |||
GI; gastrointestinal, HPF; high power field, NEC; neuroendocrine carcinoma, NET; neuroendocrine tumor, WHO; World Heath Organization.