Annular pancreas is a rare congenital anomaly. A ring of pancreatic tissue encircles the second part of the duodenum and results in varying degrees of obstruction. When the first symptoms occur in adults, they are non-specific and may consist in epigastric pain, fullness after meals, indigestion and nausea. Concomitant lesions such as ulcer or pancreatitis may obscure the diagnosis.
A case report documents that radiologic examination with barium meal disclosed the duodenal stenosis.
A properly performed CT examination revealed the ring of pancreatic tissue which encircled the duodenum. Endoscopic retrograde pancreatography may show a duct with a characteristic circular pattern around the duodenum. MR and endoscopic ultrasonography are supplementary examinations in equivocal cases.
A CT examination is a good non-invasive primary examination when annular pancreas is suspected.