Table 1 Definitions of the WHO 2017 and 2010 grading classification for p-NENs and distributions of patients in the present study according to these two criteria
Definitions | Distributions | ||
|---|---|---|---|
Classification | Mitotic rateA | Ki-67 proliferation index (%)B | Cases(%) |
WHO 2017 grading criteria [7] | |||
Well-differentiated p-NENs: | |||
NET G1 | < 2 | < 3 | 150 (31.3%) |
NET G2 | 2–20 | 3–20 | 158 (32.9%) |
NET G3 | > 20 | > 20 | 64 (13.3%) |
Poorly-differentiated p-NENs: | |||
NEC G3 (small cell and large cell subtypes) | > 20 | > 20 | 108 (22.5%) |
WHO 2010 grading criteria [8] | |||
Well-differentiated endocrine tumor, G1: | |||
NET G1 | < 2 | < 3 | 150 (31.3%) |
Well-differentiated endocrine tumor, G2: | |||
NET G2 | 2–20 | 3–20 | 158 (32.9%) |
Poorly-differentiated neoplasm: neuroendocrine carcinoma, G3 (small cell and large cell type): | |||
“NEC G3” | > 20 | > 20 | 172 (35.8%) |