Inflammatory Myofibroblastic Tumor of the Distal Bile Duct Associated with Lymphoplasmacytic Sclerosing Pancreatitis

Inflammatory myofibroblastic tumor (IMT) or inflammatory pseudotumor has been described in various organs such as the liver, intestinal tract, spleen, kidney, bladder, lung, peritoneum and heart. However, its appearance in the periampullary region is uncommon and has rarely been reported in the literature. It is characterized histologically by myofibroblastic cell proliferation together with a mixed inflammatory infiltrate that clinically and radiologically mimics a malignant tumor. We report a case of IMT located in the distal common bile duct of a 51-year-old woman. She underwent Whipple resection with the initial diagnosis of cholangiocarcinoma; the pathologic diagnosis of the tumor was IMT of the distal bile duct associated with lymphoplasmacytic sclerosing pancreatitis. Referring to previously reported cases, suspected diagnosis of a malignant tumor made surgical excision the primary choice for symptom relief and in order to obtain a definitive diagnosis. IMT relationship with lymphoplasmacytic sclerosing pancreatitis is discussed.