Abstract
An 11-year-old girl presented with a history of a pale face and easy fatigability. Physical findings showed no hepatosplenomegaly and lymph adenopathy. Examination of peripheral blood showed severe anemia with no thrombocytopenia and normal counts and differentiation of leukocytes. Bone marrow aspiration was unsuccessful. Trephin biopsy revealed marked myelofibrosis with deeply suppressed erythropoiesis, slightly increased megakaryocytes, and normal differentiation of myeloid series. Immature blasts were detected below five percent. Another notable examination was trisomy 8, which was observed in all the metaphases analyzed from unstimulated peripheral blood. Under the diagnosis of acute myelofibrosis she was mainly observed conservatively. Treatment with corticosteroid and anabolic steroid was of no benefit. Ten months later, immature blasts appeared in the peripheral blood. A diagnosis of acute myelomonocytic leukemia was made by cytochemical, immunological, and electron microscopic studies of the blasts.
