Grade | NETs appendix | Tumor differentiation |
---|---|---|
Low grade (G1) | <2 mitoses /10 high power fields (HPF) or < Ki-67 < 3%. | Well-differentiated |
Intermediate grade (G2) | 2–10 mitoses / 10 HPF or Ki-67 between 3 and 20%. | Well-differentiated |
High grade (G3) | >10 mitoses / 10 HPF or Ki-67 > 20%. | Poorly differentiated |