Derived Grade
NAACCR Item
NAACCR #1975| Code | Description |
|---|---|
| 1 | G1: Mitotic count (per 2mm2) less than 2 AND Ki-67 index (%) less than 3 Stated as WHO Grade 1 |
| 2 | G2: Mitotic count (per 2mm2) equal 2-20 OR Ki-67 index (%) equal 3-20 Stated as WHO Grade 2 |
| 3 | G3: Mitotic count (per 2mm2) greater than 20 OR Ki-67 index (%) greater than 20 Stated as WHO Grade 3 |
| A | Well differentiated |
| B | Moderately differentiated |
| C | Poorly differentiated |
| D | Undifferentiated, anaplastic |
| 9 | Grade cannot be assessed (GX); Unknown |