Annular pancreas

Case contributed by Dr Jan Frank Gerstenmaier


Recurrent pancreatitis. Gallstones were excluded on US and CT IVC

Patient Data

Age: 75 years
Gender: Male

The biliary tree remains non-dilated. There is no evidence of choledocholithiasis. The cystic duct remnant unremarkable. Soft tissue of the same signal intensity and enhancement behavior of the pancreatic parenchyma is demonstrated to encircle the duodenum.

The main pancreatic duct is non-dilated. There is no focal pancreatic lesion identified. There is no peripancreatic inflammation or fluid collection. There is a sizable duodenal diverticulum near the ampulla.

Renal cysts. Spleen, adrenal glands are normal. Hypoenhancing sub centimeter liver lesion in segment 2 is visible on HASTE, i.e. C cyst.


Annular pancreas. There is no pancreatic ductal dilatation, and currently no evidence of acute pancreatitis. No focal pancreatic lesion identified.


Biliscopin excretion has occurred. The biliary tree is of normal caliber. CBD is 7mm. Prior cholecystectomy. No evidence of choledocholithiasis. A duodenal diverticulum near ampulla is noted, measuring 2.4 cm in craniocaudal dimension. Posterior to the diverticulum is smooth deformity of the distal CBD which becomes slit like.

There is some inflammation around the distal duodenum and interior body of pancreas, as well as mild thickening of the left Gertoa's fascia, compatible with pancreatitis. Small right pleural effusion.

Conclusion: Negative for choledocholithiasis.

The gallbladder is filled with heterogeneous avascular contents likely representing biliary sludge. It also contained several mobile gallstones. The gallbladder wall is thickened. No pericholecystic fluid. Sonographic Murphy sign was negative (although the patient had generalized upper abdominal tenderness). No biliary duct dilatation (maximal CBD diameter 5.8mm).

The liver parenchyma is homogeneous in echotexture. No focal liver lesion identified.

The pancreas has a normal appearance.

The spleen measures 8.1cm.

The right and left kidneys measure 12.2cm and 11.9cm respectively. The left kidney contains three simple cysts.

Conclusion: Findings are suspicious for acute cholecystitis.

Case Discussion

Annular pancreas is a rare cause of pancreatitis and in this case the underlying condition likely responsible for recurrent episodes of pancreatitis.

The frequency of pancreas divisum is as high as 40% in patients with an annular pancreas.

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