A PREVIOUSLY HEALTHY 51-YEAR-OLD JAPANESE WOMAN was admitted to our hospital as an emergency case because of hemorrhagic shock owing to intraabdominal bleeding without any trauma. The patient was conscious, blood pressure was 56/38 mm Hg, pulse 90 beats/min, and body temperature was 36.8 C. Her abdomen was distended and diffusely tender. Rebound tenderness was noted, but the abdominal defense reflex was absent. Bowel sounds were silent and there was no flatus. The patient had a past history of 3 spontaneous abortions, but no history of laparotomy. Laboratory tests revealed a leukocyte count of 8,690/mm with 82% neutrophils and 4.5% lymphocytes, 6.6 g/dL hemoglobin, 19.3% hematocrit, and a platelet count of 11,000/mm. Coagulation tests revealed a prothrombin time of 33% (International Normalized Ratio, 2.0), activated partial thromboplastin time of 54.6 seconds, and antithrombin III of 58%. Total proteins were 4.0 mg/dL with albumin at 2.1 g/dL. The fasting blood glucose level, liver enzyme level, creatinine, uric acid, amylase, lipase, and electrolytes were within normal limits. A contrast-enhanced computed tomograph of the abdomen showed a massive collection of intraabdominal fluid, portal vein thrombosis with splenic infarction, and hypodense lesion at the periphery of the spleen which was compatible with hematoma (Fig, A). An emergency laparotomy was performed immediately after carrying out a red blood cell and