A 21-year-old young man was presented with intermittent upper abdominal pain and vomiting. A barium meal fluoroscopy was performed which showed dilatation of the proximal duodenum with marked compression in the midline of the 3rd part of the duodenum.

Image Source: Radiopedia What could be the possible diagnosis on the basis of the fluoroscopy? ​ *This case is from Docplexus Editorial Team for educative purpose only.