Down syndrome presenting with different hematological manifestations: A case series of four cases.

Children with Down syndrome (DS) are found to have an increased risk of developing various hematological disorders. Particularly, they have an increased predisposition to acute leukemia, predominantly the myeloid type known as myeloid leukemia of Down syndrome (ML-DS). The major morphological subtype is acute megakaryoblastic leukemia. Approximately 10% of the neonates with DS show a unique disorder known as transient leukemia or transient abnormal myelopoiesis (TAM). Their clinical and morphological features are indistinguishable from acute myeloid leukemia (AML); however, they regress spontaneously within the first few months of life. Here we present a series of four cases with different hematological conditions in children with DS. Of the four cases, two presented with AML-M7, one with TAM, and one case was diagnosed as AML-M2 subtype. This case series highlights the spectrum of hematological disorders in children with DS. Although the majority of the case studies show that TAM and AML-M7 are strongly associated with DS, this case series brings to focus that other AML subtypes may occur as well.