Idiopathic Acquired Hemophilia A with Undetectable Factor VIII Inhibitor

Acquired factor VIII deficiency in prostate adenocarcinoma presenting as multiple hematomas and hemarthrosis

Acquired hemophilia A or acquired factor VIII deficiency is a rare bleeding disorder due to the presence of autoantibodies to factor VIII. It has been associated with autoimmune conditions, certain medications, and malignancy. It has a high morbidity and mortality, and early diagnosis and treatment is critically important. Acquired hemophilia A usually manifests with soft tissue bleeding, such as epistaxis, genitourinary, or gastrointestinal bleeding and rarely with hemarthrosis. In this case report, we present the management of an uncommon case of acquired hemophilia A in a patient with metastatic prostate adenocarcinoma who presented with both hemarthrosis and soft tissue bleeding. Bleeding was controlled with recombinant factor VIIa, factor VIII bypassing agent, and immunosuppressive therapy with prednisone and rituximab. Chemotherapy with docetaxel was also promptly initiated to address the underlying condition and achieve long-term remission, which is currently ongoing for 10 months.