Genetic Landscape of Acute Leukemia of Ambiguous Lineage

Acute leukemias of ambiguous lineage (ALALs) are rare acute leukemias with poor prognosis, encompassing acute undifferentiated leukemia and mixed-phenotype acute leukemia. The fifth edition of the World Health Organization classification of hematolymphoid tumors recommends excluding ALAL cases with myelodysplasia-associated mutations and/or cytogenetic abnormalities from classification as acute undifferentiated leukemia or mixed-phenotype acute leukemia, instead categorizing them as acute myeloid leukemia with myelodysplasia (AML-MR; hereafter referred to as AML-MR/ALAL), a distinct entity with limited genetic and clinical characterization to date.