Abstract
Transient abnormal myelopoiesis (TAM) in newborns with Down syndrome (DS) often presents mildly and is managed symptomatically, but in rare cases, it can progress aggressively, requiring treatment with low-dose cytarabine. Here, we report a case of TAM that progressed aggressively despite 2 rounds of low-dose cytarabine treatment. Although the blast count decreased from 60% to 1%, the patient's liver failure worsened, ultimately leading to his death. Recent advancements in understanding and managing TAM have improved overall prognosis, yet liver failure remains a challenging prognostic indicator.