Classification updates to the lineage markers
| . | . | . | WHO-HAEM5 . | ICC classification . |
|---|---|---|---|---|
| B lineage | Strong CD19 and | 1 or more marker expressed: CD10, CD22 or CD79a | CD19 intensity in part exceeds 50% of normal B-cell progenitor by flow cytometry | CD19 expression should be at least similar to that seen in stage I B-cell precursors or mature B-cells |
| Weak CD19 and | 2 more strongly expressed: CD10, CD22, CD79a | |||
| Consider immunohistochemical stains for B-lineage PAX5, OCT2, BOB1 | ||||
| T lineage | CD3 (surface or cytoplasmic) | Intensity in part exceeds 50% of mature T-cell level by flow cytometry | ||
| Myeloid lineage | MPO or | MPO intensity in part exceeds 50% of mature neutrophil level Immunocytochemistry positive with non-zeta chain reagent | ||
| Monocytic differentiation | NSE, CD64, CD11c, CD14 or lysozyme |
| . | . | . | WHO-HAEM5 . | ICC classification . |
|---|---|---|---|---|
| B lineage | Strong CD19 and | 1 or more marker expressed: CD10, CD22 or CD79a | CD19 intensity in part exceeds 50% of normal B-cell progenitor by flow cytometry | CD19 expression should be at least similar to that seen in stage I B-cell precursors or mature B-cells |
| Weak CD19 and | 2 more strongly expressed: CD10, CD22, CD79a | |||
| Consider immunohistochemical stains for B-lineage PAX5, OCT2, BOB1 | ||||
| T lineage | CD3 (surface or cytoplasmic) | Intensity in part exceeds 50% of mature T-cell level by flow cytometry | ||
| Myeloid lineage | MPO or | MPO intensity in part exceeds 50% of mature neutrophil level Immunocytochemistry positive with non-zeta chain reagent | ||
| Monocytic differentiation | NSE, CD64, CD11c, CD14 or lysozyme |
The immunophenotypic criteria described here are for cases of suspected MPAL and are not required for straightforward cases of AML or ALL.