Nottingham Grading Calculator
Modified Bloom–Richardson histologic grade for invasive breast carcinoma, color-coded by grade.
Free with an accountLog in to calculate. You can explore the inputs and reference material below; results need a free student account.
For educational and research purposes. Calculates histological grade only — not TNM stage. Does not replace professional histopathological assessment or institutional diagnostic protocols.
Reference
About Nottingham grading
The Nottingham (Modified Bloom–Richardson / Elston–Ellis) system grades invasive breast carcinoma from three independently scored components — tubule formation, nuclear pleomorphism, and mitotic count.
Histological grade is distinct from TNM stage: grade describes differentiation under the microscope; stage describes tumor extent and spread.
Tubule formation
| Score | Criteria |
|---|---|
| 1 | >75% of tumor forms tubules |
| 2 | 10–75% of tumor forms tubules |
| 3 | <10% of tumor forms tubules |
Nuclear pleomorphism
| Score | Criteria |
|---|---|
| 1 | Small, uniform nuclei with minimal variation |
| 2 | Moderate variation in nuclear size and shape |
| 3 | Marked nuclear enlargement/pleomorphism with considerable variation |
Mitotic count thresholds
Mitotic scoring cutoffs depend on microscope field diameter/area and the reference protocol in use. The default thresholds are an editable example only — verify and set your institution’s validated thresholds before any clinical use.