Obstructive chronic pancreatitis secondary to a duodenal duplication cyst containing the ampulla

s / Pancreatology 15 (2015) e1ee17 e10 brush cytology of the common bile duct was negative for malignancy. Tumor markers were negative and IgG4 levels were not measured. Results: A cephalic pancreaticoduodenectomy was performed and a pancreatic head tumor was found. Histology revealed plasmacytic infiltration of the pancreatic parenchyma, gallbladder and bile and cystic ducts with a predominance of IgG4-positive plasma cells (90/high-power field). Final diagnosis was a lymphoplasmacytic sclerosing pancreatitis with biliary involvement. Discussion: IgG4-associated cholangitis is a rare type of AIP associated with bile duct involvement with or without pancreatic affection that responds well to steroids therapy, so it is important to rule out AIP in the diagnostic work-up of an EC to avoid unnecessary surgeries.