Major duodenal papilla is a conic or cylindric protuberance at the medial aspect of the descending or horizontal duodenum at the site of the sphincter of Oddi. It is finding on small bowel follow-though (and endoscopy) and has a relatively long differential.
On cross sectional imaging, the underlying cause is usually seen before the effect on the papilla.
- normal variant
- patulous ampulla of Vater (look for associated pneumobilia)
- autoimmune pancreatitis
- impacted choledocholithiasis