Groove Pancreatitis-MR & CT

56 years old adult male with history of repeated upper abdominal pain with unremarkable sonography. Case submitted by Dr MGK Murthy. 

The CT and MR demonstrate features suggestive of groove pancreatitis :

-  Widening of the pancreaticoduodenal groove.
-  Mild hypointensity on MR of the duodenal wall.
-  Proximal stomach dilatation and possibly proximal duodenum.
-  Mild tapering of the common duct.
-  Pancreatic duct suggest possibly mass effect in the head region with rest of the duct normal and no peripancreatic fluid collections.
-  The MRCP shows heterogenity, enlarged head region, with focal cyst formation.
-  No dilatation of accessory pancreatic duct.
-  Banana shaped gall bladder due to stasis with no cholelithiasis.

The differential diagnosis of pancreas divisum is excluded by nondilated accessory pancreatic duct. Adenocarcinoma, duodenitis need follow up to exclude.

Upper GI series, Endoscopic sonography would help.

The etiology is ill-understood with possibly repeated bowel ulcerations, ressection, heterotopic pancreatic tissue, transient cyst formation with definite biochemical consistency.