Spontaneous retroperitoneal hemorrhage in a mediastinal tumor in a patient with polymyositis: a case report.

Spontaneous retroperitoneal hemorrhage is a lethal cause of acute abdomen that is most frequently related to drugs, coagulopathy and intra-abdominal tumors. In patients with polymyositis and dermatomyositis, acute abdomen is attributed to intestinal vasculitis causing ischemia, ulceration or perforation. Spontaneous retroperitoneal hemorrhage, however, has rarely been reported in patients with polymyositis. We report the case of a 65-year-old woman with newly diagnosed polymyositis and suspected thymoma who suffered from spontaneous retroperitoneal hemorrhage. She experienced two massive retroperitoneal hemorrhage episodes within 24 hours, which resulted in shock and required emergent angiographic embolization. There was no evidence of tumor, vasculitis or aneurysm from abdominal angiography and computed tomography.