Transient Abnormal Myelopoiesis: Aggressive and Potentially Lethal Progression-A Case Report.

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.