2015 Volume 18 Issue 2 Pages 42-50
A 37-year-old man was referred to our department with pancytopenia. His hemoglobin level was 5.6 g/dL, white blood cell count was 2.41 × 103/µL, and platelet count was 32.0 × 103/µL. A blood smear examination revealed significantly large numbers of schistocytes and marked anisopoikilocytosis. His bone marrow contained 37.0% blasts with the morphological and cytochemical characteristics of proerythroblasts, and showed trilineage dysplasia. Flow cytometric and electron microscopic analyses provided persuasive evidence for the immature erythroid features of blasts. Metaphases obtained from the bone marrow carried complex cytogenetic abnormalities, including del(5q) and −7, both of which were detected in approximately 70% of bone marrow cell nuclei by fluorescence in situ hybridization. The patient was treated with induction chemotherapy consisting of cytarabine and idarubicin, leading to a complete hematological response and the normalization of erythrocyte morphology. Schistocytosis as well as anisopoikilocytosis in the blood may reflect defective erythrocyte development in the bone marrow. Despite the erythroid features of the blasts, the presence of del(5q) and −7, and the trilineage dysplasia indicated that the leukemia of this case was acute myeloid leukemia with myelodysplasia-related changes, according to the current WHO classification.