Spontaneous remission of congenital acute megakaryoblastic leukemia in a neonate with down syndrome

Objectives Congenital acute megakaryoblastic leukemia (AMKL) is an extremely rare and aggressive malignancy with poor prognosis. Case presentation We report a female neonate with Down syndrome (DS) who presented with respiratory distress and hepatomegaly at birth. Laboratory evaluation revealed hyperleukocytosis (253.45 × 10 9 /L) and bone marrow studies confirmed AMKL with trisomy 21. Remarkably, spontaneous hematologic remission occurred within 2 months without chemotherapy. Conclusions This case highlights the unique clinical course of DS-associated AMKL and underscores the potential for spontaneous regression in congenital leukemia.