Table 1.
Pathological classification of neuroendocrine neoplasms: comparison between the editions of WHO 2010 and 2019.
| WHO 2010 | Ki-67 Index | Mitotic count /10 HPF | WHO 2019 | Ki-67 Index | Mitotic rate (mitoses/2 mm2) |
| Well-differentiated NENs | Well-differentiated NENs | ||||
| NET grade 1 | <3 | <2 | NET grade 1 | <3 | <2 |
| NET grade 2 | 3–20 | 2–20 | NET grade 2 | 3–20 | 2–20 |
| NET grade 3 | >20 | >20 | |||
| Poorly differentiated NENs | Poorly differentiated NENs | ||||
| NEC grade 3 | >20 | >20 | NEC grade 3 | >20 | >20 |
| MANECs | MiNENs |
HPF = high power fields, MANEC = mixed adeno-neuroendocrine carcinoma, MiNEN = mixed endocrine non-endocrine neoplasm, NEC = neuroendocrine carcinoma, NEN = neuroendocrine neoplasm, NET = neuroendocrine tumor, WHO = World Health Organization.