Molecular and Immunophenotypic Characteristics of Adult Acute Leukemias of Ambiguous Lineage

Acute undifferentiated leukemia (AUL) and mixed phenotype acute leukemia (MPAL) are acute leukemias of ambiguous lineage representing less than 5% of all adult leukemias. Ontogenetically, they are thought to be caused by precursor lesions in early pluripotent hematopoietic progenitor cells having the ability to differentiate into both lymphoid and myeloid lineages. In contrast, common lymphoid and myeloid leukemias are likely derived from precursor lesions in committed progenitor cells. The molecular characteristics of the cell of origin of these leukemias have not been fully characterized.