Abstract
A 39-year-old man with abdominal pain was admitted to our hospital with a diagnosis of acute enteritis. None of the laboratory tests or imaging findings were abnormal except for marked leukocytosis of 13, 100cells/mm3. He was treated with antibiotics for few days, and the symptoms and laboratory findings improved. After oral feeding was resumed, the abdominal pain worsened and he developed signs of peritonitis. Contrast-enhanced CT scans on the 11th hospital day showed a large volume of ascitic fluid, thickened small bowel, and thrombi in the superior mesenteric vein. Laparotomy was performed for a preoperative diagnosis of acute peritonitis secondary to mesenteric vein thrombosis. Congestive necrosis of 25cm of ileum and 35cm of jejunum was observed intraoperatively, and they were resected to healthy margins. Intestinal continuity was restored by end-to-end anastomosis. Histopathological examination showed transmural hemorrhagic necrosis of the small bowel and thrombi in the superior mesenteric vein. Laboratory studies showed low levels of protein S activity (11%) and protein S antigen (24.2%). Because the patient had no underlying disease that might have caused the thrombosis, we concluded that this was a rare case of the mesenteric vein thrombosis associated with protein S deficiency.
