Acute Leukemias of Ambiguous Lineage: Clarification on Lineage Specificity

Abstract

Acute leukemias of ambiguous lineage (ALAL) include acute undifferentiated leukemia and mixed-phenotype acute leukemia (MPAL). This article provides an overview of the diagnosis of ALAL and focuses on the data accounting for the current lineage-assignment criteria for blasts harboring more than one lineage-associated marker. In addition, the currently known molecular data are reviewed, which show that MPAL-associated gene mutations, methylation signatures, and expression profiles are a mixture of those seen in both acute myeloid leukemia and acute lymphoblastic leukemia. Finally, the prognosis and current treatments of MPAL are briefly discussed.

Keywords: Acute undifferentiated leukemia; KMT2A; Lineage; Mixed phenotype acute leukemia.