Grading of CNS disease per the COG classification system
| Grade of CNS disease at diagnosis . | Definition . |
|---|---|
| CNS-1 | No blasts in the CSF (regardless of WBC or RBC count in CSF) |
| CNS-2 | |
| a | <5 WBC per μL + blasts + <10 RBC per μL∗ |
| b | <5 WBC per μL + blasts + >10 RBC per μL |
| c | ≥5 WBC per μL + blasts + ≥10 RBC per μL; CSF WBC <2 × peripheral blood WBC |
| CNS-3 | |
| a | ≥5 WBC per μL + blasts + <10 RBC per μL |
| b | ≥5 WBC per μL + blasts + ≥10 RBC per μL; CSF WBC >2 × peripheral blood WBC |
| c | Clinical evidence of CNS disease† |
| Grade of CNS disease at diagnosis . | Definition . |
|---|---|
| CNS-1 | No blasts in the CSF (regardless of WBC or RBC count in CSF) |
| CNS-2 | |
| a | <5 WBC per μL + blasts + <10 RBC per μL∗ |
| b | <5 WBC per μL + blasts + >10 RBC per μL |
| c | ≥5 WBC per μL + blasts + ≥10 RBC per μL; CSF WBC <2 × peripheral blood WBC |
| CNS-3 | |
| a | ≥5 WBC per μL + blasts + <10 RBC per μL |
| b | ≥5 WBC per μL + blasts + ≥10 RBC per μL; CSF WBC >2 × peripheral blood WBC |
| c | Clinical evidence of CNS disease† |