Multiple myeloma presenting with acquired factor VIII inhibitor.

An initial presentation of hematological malignancies associated with autoantibodies is not common, and there is only one documented case of multiple myeloma presenting with acquired FVIII inhibitor for multiple myeloma. In this paper, we describe a second case of multiple myeloma who presented with acquired FVIII inhibitor. A 43-year-old woman was referred to our hematology unit for anemia and an elevated erythrocyte sedimentation rate. Two months before her admission, she had undergone an operation at a local hospital because of ovarian cyst rupture complicated by severe postoperative bleeding. Because coagulation tests had revealed a prolonged partial thromboplastin time which could not be corrected by a mixing test and a decreased FVIII level, a diagnosis of acquired FVIII inhibitor had been made. The patient was hospitalized in our unit for further evaluation. The erythrocyte sedimentation rate was 110 mm/h, serum albumin level 2.5 g/dL, globulin level 5.6 g/dL, and C-reactive protein 47.8 mg/L (0-6). Serum IgG was high, and serum protein electrophoresis showed a monoclonal spike in the gamma region. An IgG-kappa paraprotein was identified by immunofixation of the urine and serum. X-ray films of the bones revealed lytic areas in the skull, pelvis, and lumbar vertebrae. Bone marrow aspiration showed normal cellularity with 40% plasma cell infiltration. The patient was diagnosed with the IgG kappa type of multiple myeloma associated with acquired FVIII inhibitor. In patients presenting with severe bleeding, autoantibodies against FVIII should be considered for the differential diagnosis of bleeding. Clinicians should be alert to the presence of rare underlying neoplastic diseases such as multiple myeloma, in patients with acquired FVIII inhibitor.