A Case of Acquired von Willebrand Disease Secondary to Myeloproliferative Neoplasm.

Acquired von Willebrand Disease (AVWD) is a rare disorder in which qualitative or quantitative defects in von Willebrand factor (VWF) occur secondary to other conditions. AVWD occurs in patients with myeloproliferative disorders due to formation of autoantibodies against VWF and development of excessive shear stress causing disruption of VWF multimers. AVWD is different from congenital VWD in its acute onset and absence of family history. We report a 42-year-old gentleman with essential thrombocythemia, who was on cytoreductive therapy with hydroxyurea, and presented with an acute history of gum bleeding with hemoptysis, without any antecedent trauma or infections. His platelet count was very high, and prothrombin time and activated partial thromboplastin time were prolonged. The VWF ristocetin cofactor assay (VWF: RCo) was low, but VWF antigen level (VWF: Ag) was normal. Their ratio (VWF: RCo/VWF: Ag) was much lower than the acceptable lower limit. Treatment in AVWD is focused on addressing the underlying disorder. Early recognition of AVWD and its primary cause is mandatory in providing adequate therapy and achieving a cure.