Acute megakaryoblastic leukemia with increased hematogones in children.

We describe 2 patients, a 4-month-old male and a 17-month-old female, with de novo acute megakaryoblastic leukemia with increased number of hematogones at diagnosis. Both children were admitted in the hospital with thrombocytopenia. The bone marrow smears in the first child revealed the presence of 60% cells with morphologic features consistent with acute megakaryoblastic leukemia. In the other, the initial bone marrow aspirate was dry tap but on the following aspirate 10% cells with lymphoblastic morphology could be seen. The bone marrow flow cytometry showed the presence of hematogones-38% in the first case and 20% in the second-with absence of blasts. Repeated bone marrow aspirates, trephines, and immunophenotypic as well as molecular studies, confirmed the diagnosis of M7. Both children were treated according to the Berlin-Frankfurt-Munster 2004 protocol.