Table 19

Criteria for lineage assignment for a diagnosis of MPAL

Lineage assignment criteria
Myeloid lineage
 MPO* (flow cytometry, immunohistochemistry, or cytochemistry)
 or
 Monocytic differentiation (at least 2 of the following: nonspecific esterase cytochemistry, CD11c, CD14, CD64, lysozyme)
T-lineage
 Strong cytoplasmic CD3 (with antibodies to CD3 ε chain)
 or
 Surface CD3
B-lineage
 Strong CD19 with at least 1 of the following strongly expressed: CD79a, cytoplasmic CD22, or CD10
 or
 Weak CD19 with at least 2 of the following strongly expressed: CD79a, cytoplasmic CD22, or CD10
  • * See “Acute leukemias of ambiguous lineage” for caveats related to weaker antigen expression, or to expression by immunohistochemistry only.

  • Strong defined as equal or brighter than the normal B or T cells in the sample.