Diagnostic criteria for BAL and MPAL. (A) EGIL criteria for the diagnosis of biphenotypic acute leukemia.^a (B) 2008 WHO criteria. Leukemias that fail to demonstrate differentiation along a single lineage are defined as acute leukemias of ambiguous lineage (ALAL) and are further subdivided into diagnostic subgroups. A practical approach for the diagnosis of MPAL is presented.