Clinical Features, Laboratory Characteristics, And Response To Therapy In Patients With Acute Undifferentiated Leukemia

Introduction: Acute undifferentiated leukemia (AUL), also referred to as ambiguous lineage leukemia, has been recognized as a unique entity by the WHO classification of myeloid neoplasms since 2008, and is considered a rare subtype. It is characterized by lacking expression of markers diagnostic of myeloid or lymphoid lineages, and encompasses the provisional entity of myeloid/natural killer (NK) leukemia, which also expresses CD56 and other immature T-cell markers. Small studies have reported that AUL is associated with a poor prognosis; however, cytogenetic and molecular characterization of this subgroup of patients is lacking, as are the long-term outcomes of induction therapy and stem cell transplantation (SCT). The goal of this study was to assess clinical and laboratory data of patients diagnosed with AUL at our institution, focusing on its unique characteristics and response to initial therapy.