A case of adult acute myelocytic leukemia (M5a) with a near-tetraploid karyotype characterized by monosomies 5 and 16

Whereas hyperdiploidy is a frequent cytogenetic abnormality in acute lymphoblastic leukemia, tetraploidy is rarely observed in acute myeloblastic leukemia (AML), in which gains and losses of whole chromosomes do occur frequently [1–4]. A 76-year-old man was admitted to our division with dyspnea and weakness. Peripheral blood cell analysis showed white blood cell count 29.6 × 10/mL with 90% blast cells, hemoglobin 9.4 g/dL, and platelets 55 × 10/mL. Physical examination findings were normal, except for liver enlargement. Bone marrow examination confirmed a diagnosis of AML M5a with 90% blast cells. Leukemic cells