Nottingham Grading System
| Parameter | Description |
| Characteristic | |
| Tubule formation | Amount of tumor tissue with normal breast (milk) duct structures |
| Nuclear grade | Size and shape of nucleus in tumor cells |
| Mitotic rate | Number of dividing cells (measure of how fast tumor cells grow and divide) |
| Points* | |
| 1 | Cells and tumor tissue look most normal |
| 3 | Cells and tumor tissue look most abnormal |
| Grade | |
| 1 (3–5 total points) | Low (well differentiated; slower growing, less likely to spread) |
| 2 (6–7 total points) | Intermediate (moderately differentiated) |
| 3 (8–9 total points) | High (poorly differentiated; faster growing, more likely to spread) |
*Points are assigned to tumor for the 3 characteristics. Total score ranges from 3 to 9, corresponding to grade 1, 2, or 3 (11,49).