Congenital leukemia of fetus with acquired AML1 gene duplication

Congenital leukemia is very rare, and its prevalence according to recently published papers is from 1 to 5 per million live births. This can be often diagnosed in postpartum throughout bone marrow biopsy, showing abnormal proliferation of immature blasts and granulocytic precursors. Hepatosplenomegaly is the most common feature which is found during perinatal examinations, that diagnosing is difficult during perinatal period. Hepatosplenomegaly can occur not only in congenital leukemia but in many other cases such as infection which is the most common cause. In other words, congenital leukemia is the one of the rare causes of hepatosplenomegaly. However, this case shows the fetus with the features of hepatosplenomegaly during perinatal period and being diagnosed as congenital leukemia associated with acquired AML1 gene duplication in postpartum through bone marrow biopsy. Due to its rare instance, we are to describe the case with a review of literatures.