Introduction
Superior mesenteric syndrome is not a very common disease but it has a relatively simple pathophysiology.  Being compressed by SMA from above to underlying structures of retro peritoneum like abdominal aorta, third part of duodenum is obstructed and causes the patient acute, or chronic and intermittent symptoms of obstruction.
Case report
A 24 years old man with 4 years history of dysphagia to solid foods, complained of weight loss, semi liquid food dysphagia dysphonia and eyelid ptosis.
In upper GI endoscopy; esophagus was normal, stomach was dilated and clues of food stasis were seen. Endoscopic Biopsies were normal. The patient underwent CT scanning in which stenosis of third part of the duodenum and dilatation of the proximal part to the stenosis are seen. After 3D reconstruction of CT scan images, it was noticed that the angle of origin of superior mesenteric artery from aorta was decreased.
Conclusion
predisposing factor to superior mesenteric syndrome is excessive cachectia and since MNGIE syndrome appears with dysphagia, malnutrition and cachectia, the fat pad between aorta and superior mesenteric artery regresses and this can results in superior mesenteric artry syndrome.