A CASE OF MESENTERIC ARTERY ANEURYSM PRESENTING WITH BLOODY STOOL DUE TO ISCHEMIA OF THE TRANSVERSE COLON CAUSED BY AN INTERMESENTERIC HEMATOMA

A 44-year-old male was admitted to the hospital because of bloody stool lasting for several days. On admission, no anemia was found. Ultrasonography and CT revealed an abdominal mass with a small amount of interabdominal fluid. He suddenly developed abdominal pain with signs of shock and emergency laparotomy was done. Upon operation there were a large quantity of hemorrhage in the abdominal cavity, extensive hematoma in the transverse mesocolon, laceration of the posterior leaf of the transverse mesocolon, and a fist-sized clot in the same region. A definite bleeding source was not identified. The transverse colon including the hematoma was resected. Histopathologically, a ruptured aneurysm was seen in the mesocolon and crypt abscess was seen in the mucosa of transverse colon. Its submucosa was edematous. Aneurysms of the mesenteric artery are rare. Most of them undetected until some symptoms such as gastrointestinal bleeding or interabdominal hemorrhage occur. Gastrointestinal bleeding is usually caused by aneurysmal rupture into the gastrointestinal tract. This case is thought rare, because the bloody stool seen on admission might be caused not by rupture of the aneurysm into the transverse colon but by ischemia due to intermesenteric hematoma.