Acquired von Willebrand syndrome in a myeloproliferative disorder. Case 6.

We present a woman (age: 57 years) with an excessive bleeding episode under acetylsalicylic acid after bone marrow puncture due to an acquired von Willebrand syndrome (avWS) in the context of a myeloproliferative disorder. The laboratory features showed a high platelet concentration and a qualitative defect of von Willebrand factor (vWF) with a low normal vWF ristocetin cofactor activity, a normal vWF antigen and a decrease of the larger vWF multimers in plasma. The exact mechanism of avWS is still incompletely resolved. Myeloproliferative diseases are one of several underlying disorders that may cause avWS. The diagnosis of the underlying disease is important because its treatment may lead to an improvement of the vWF abnormality. For symptomatic treatment of bleeding, desmopressin, vWF concentrate infusion, intravenous immunoglobulin and/or fibrinolysis inhibitors can be tried.