Hemophagocytic syndrome with erythrocyte phagocytosis by the myeloid precursors in a patient with AML -M2.

Hemophagocytic syndrome is characterized by fever, fatigue, weight loss, lymphadenopathy, and laboratory abnormalities including pancytopenia, liver dysfunction, hypertriglyceridemia and hyperfibrinemia. Histopathologically, lesions are characterized by mononuclear cell infiltration with marked histiocyte proliferation and phagocytosis of erythrocytes, leukocytes, platelets and their precursors by activated macrophages in the reticuloendothelial tissues. Hemophagocytic syndrome may develop from strong immunological stimuli such as severe infection, malignancy and autoimmune diseases. We present a 73-year-old man with acute myeloblastic leukemia FAB M2 type (AML M2) whose bone marrow histology showed unusual hemophagocytosis by myeloid cells and myeloblasts.