Grading schemes

Question 1

Neuroendocrine tumors of the GI tract

Answer 1

• Grade 1 NET: <2 mitoses/10HPF and < 2% Ki-67 index
• Grade 2 NET: 2-20 mitoses/10HPF and/or 3-20% Ki-67 index
• Grade 3 neuroendocrine carcinoma (NEC): >20 mitoses/10HPF and/or >20% Ki-67 index

* It is recommended that these parameters are assessed over 50 HPF

*2010 WHO grading system