Huge multinucleated megaloblasts found in a patient with refractory anemia with excess blasts-1

摘要

A 68-year-old male was hospitalized with palpitations and lightheadedness. Laboratory tests showed macrocytic anemia (hemoglobin concentration 71g/L with a mean corpuscular volume of 106.2 fl) and thrombocytopenia (platelet count 24.0 x 109/L). The leukocyte count was 7.0 x 109/L (neutrophil 80 %, lymphocyte 15 %, mono-cyte 4 %, myeloblast 1 %). Serum levels of vitamin B_12 and folic acid were within the normal range.The blood smear demonstrated anisocytosis of the erythrocytes with macrocytes and poikilocytes, such as target cells and fragmented cells (Fig. la). The bone marrow examination showed hypercellular marrow with dominant proliferation of erythroid lineage cells (72.3 %), which had dysplastic features, including megaloblastoid changes, multinucleation and karyorrhexis (Fig. lb, c). Elastic cells accounted for 1.8 % of the bone marrow nuclear cells (7.8 % in non-erythroid cells). They were negative for peroxidase staining.