Bilateral recurrent external obturator muscle hematoma: An unusual cause of pelvic pain in hemophilia.

Following joint hemorrhages, intramuscular hemorrhages are the second most prevalent bleeding pattern in hemophiliac patients. Hematomas of the iliopsoas muscle are a well-known complication of hemophilia; however, obturator muscle hematomas are rare. We herein report a case of spontaneous bleeding of the bilateral external obturator muscles, which occured three times within a period of 9 months in a hemophilia patient with factor VIII inhibitors. To the best of our knowledge, this is the first published case of an obturator externus muscle hematoma in hemophilia. In addition to hip hemarthrosis, iliopsoas hematomas and acute appendicitis, obturator muscle hematoma should be considered as one of the diagnostic alternatives for pelvic pain in hemophiliaψ patients. Magnetic resonance imaging enables rapid diagnosis of obturator muscle hematoma.