WHO NET Classification: 2010 vs. 2017 (23)
| WHO classification | Ki-67 index | Mitoses/ 10 HPFs |
|---|---|---|
| 2010 | ||
| Well-differentiated NENs | ||
| NET G1 | <3 | <2 |
| NET G2 | 3–20 | 2–20 |
| Poorly differentiated NENs | ||
| NEC G3 (small cell or large cell) | >20 | >20 |
| MANEC | ||
| 2017 | ||
| Well-differentiated NENs | ||
| NET G1 | <3 | <2 |
| NET G2 | 3–20 | 2–20 |
| NET G3 | >20 | >20 |
| Poorly differentiated NENs | ||
| NEC G3 | >20 | >20 |
| Small cell type | ||
| Large cell type | ||
| MiNEN |
HPF = high-power field.