Vomiting and rapid weight loss in a man with newly diagnosed HIV infection.

Diagnosis: Superior mesentartic artery (SMA) syndrome. The radiographic and CT findings (figures 1 and 2) are consistent with SMA syndrome. This is an infrequent cause of highintestinal obstruction that occurs in association with a period of rapid weight loss. Although initially described in the 1820s [1], its status as a true clinical syndrome was not confirmed until the late 1960s, with improvement in radiologic techniques. The third portion of the duodenum is held fixed by the ligament of Trietz. It is situated between the superior mesenteric artery, to the anterior, and the aorta, to the posterior. The angle at which the superior mesenteric artery separates from the aorta is normally maintained by intraperitoneal fat and lymphatic tissue. A loss of fat in this area, which can occur in severe malnourishment and cachexia, can cause the angle to become more acute, resulting in compression of the duodenum. Common symptoms of SMA syndrome are postprandial epigastric pain and fullness and voluminous vomiting [2]. SMA syndrome has been previously reported in association with