[Acquired paraneoplastic hemophilia secondary to Vater's ampulla adenocarcinoma].

Acquired hemophilia A is an unusual bleeding disorder of autoimmune origin resulting in the formation of autoantibodies directed against coagulation factor VIII. These autoantibodies can act by partially or completely neutralizing the activation or function of the factor, or they can also accelerate its elimination from the circulation. The global incidence of the disease is 1.5 cases per million inhabitants per year. In nearly 50% of cases, an underlying disease that is presumed responsible to produce autoantibodies can be detected. We report a case with acquired hemophilia A, in a patient with Vater's ampulla adenocarcinoma.