A case of acquired hemophilia diagnosed after thyroid tumor surgery

Acquired hemophilia A is a bleeding disorder characterized by the development of autoantibodies to coagulation factor Ⅷ and presenting with bleeding symptoms. Herein, we report a case of acquired hemophilia A in a 65-year-old female in whom hematoma in the rectus abdominis muscle was found after surgery for a thyroid tumor. Acquired hemophilia A may have a fatal course due to bleeding, so early diagnosis and early treatment are desirable. Although unfamiliar to otolaryngologists, it is important to suspect this disease in patients with no bleeding diathesis who have normal platelet counts and PTs and only APTT prolongation.