TABLE 1.
Change of Terminology in World Health Organization (WHO) Classifications of Gastroenteropancreatic Neuroendocrine Tumors
| WHO 2000 | WHO 2010
|
||
|---|---|---|---|
| Term and Grade | No. of Mitosesa | Ki-67 Indexb | |
|
| |||
| Well-differentiated endocrine tumor | Neuroendocrine tumor (carcinoid) | ||
| Well-differentiated endocrine carcinoma | Grade 1 | < 2 | ≤ 2 |
| Grade 2 | 2–20 | 3–20 | |
| Poorly differentiated endocrine carcinoma (small cell carcinoma) | Neuroendocrine carcinoma (small cell or large cell), grade 3 | > 20 | > 20 |
| Mixed exocrine-endocrine carcinoma | Mixed adenoneuroendocrine carcinoma | ||
Note—Criteria summarized in [6].
a
Per 10 high power fields (high power field = 2 mm2 at 400× magnification in hotspot areas).
b
Percentage of stained cells among 500–2000 tumor cells in hotspot areas.