WHO Grade (Neuroendocrine Neoplasm, Ki-67 and mitoses)

WHO 2022 grade for a gastroenteropancreatic neuroendocrine neoplasm (Rindi 2022).

Open the calculator → Runs in your browser. Data leaves only if you deliberately send a problem report from the interactive tool.

Example

Differentiation
Well differentiated (a neuroendocrine tumor, graded below)
Ki-67 index
25 %
Mitoses per 2 mm2
1

Result: NET G3 - the Ki-67 index drives the grade up: Ki-67 gives G3 where the mitotic count alone gives G1.

The tool opens with these values already filled in. Replace them with your own.

What the result means

G1
Under 2 mitoses per 2 mm2 AND a Ki-67 under 3%.
G2
2 to 20 mitoses OR a Ki-67 of 3 to 20%.
G3
Over 20 mitoses OR a Ki-67 over 20%.
Higher wins
The higher of the two indices sets the grade. A Ki-67 of 25% with a single mitosis is still G3.
Differentiation
A separate axis deciding the ENTITY. Well differentiated is a NET and is graded; poorly differentiated is a NEC, high grade by definition and typed small-cell or large-cell on morphology.

What you enter

  • Differentiation
  • Ki-67 index
  • Mitoses per 2 mm2
How this is calculated

Rindi G, Mete O, Uccella S, et al. Overview of the 2022 WHO classification of neuroendocrine neoplasms. Endocr Pathol. 2022;33(1):115-154. Read the source ↗

A reference and educational tool. Not medical, legal, or financial advice, and not a substitute for clinician judgment.

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Built by Clay Good. Source on GitHub.