Abstract
A 58-year-old female was referred to us because of M-proteinemia and anemia. Bone marrow showed normocellularity with 14.8% of atypical plasma cells. Serum electrophoresis on cellulose acetate membrane revealed a single M-peak (56.9%). Immunoelectrophoresis showed large M-bows against anti-IgA and anti-λ, together with small M-bows against anti-IgG and anti-κ of the same electrophoretic mobility. In the urine, λ type Bence Jones protein was found. The skull X-ray showed multiple punched out lesions. APTT was 61 seconds, fibrinogen 118 mg/dl, factor VIII clotting activity 25% with normal factor VIII related antigen, and factor IX clotting activity 38%. Circulating anticoagulants were not detected. These hemostatic abnormalities were thought ascribable to the interference of clotting activities by paraproteins. On the 33rd hospital day, she suffered from intracerebral hemorrhage, which was possibly due to these hemostatic abnormalities.