Department of Hematology, Postgraduate Institute of Medical Education and Research, Chandigarh, India.
A 30-year-old woman presented with fever and fatigue. She had pallor, gum hyperplasia, and hepatosplenomegaly along with anemia (hemoglobin 7.7 g/dL), thrombocytopenia (63×109/L), and leukocytosis (20.7×109/L). Her marrow aspirate had 76% blasts, many showing single, long, slender Auer rods. Dysgranulopoiesis was noted
Multiple ingested intact Auer rods in histiocytes may be seen in promyelocytic leukemias during therapy. Auer rods are composed of the myeloperoxidase enzyme in a crystalline form, which may resist digestion by the enzymes in the histiocytes and thus persist. Extensive phagocytic activity, as evidenced by multiple Auer rods within the macrophages in non-promyelocytic leukemias as seen in this case, is an unusual occurrence.