A case with multiple myeloma complicated with hemophagocytic syndrome (HS) is presented. Because pancytopenia, liver dysfunction and increase of mature histiocytes in the bone marrow appeared rapidly a diagnosis of HS was made. The patient died of multiple organ failure, despite steroid therapy. Autopsy revealed marked invasion of hemophagocytic histiocytes not only into the bone marrow but also into many other organs such as the liver, lymph nodes and kidneys. HS is a histiocyte proliferative disorders, which is likely to be seen in immunocompromised hosts, but there is no previous report about HS and multiple myeloma.
