title: Autoimmune pancreatitis with response to chemoradiation therapy.
abstract: Autoimmune pancreatitis (AIP) sometimes mimics pancreatic cancer, and is rarely resected under this misdiagnosis. However, there is no report in the literature regarding a case of AIP, which was misdiagnosed as an inoperative stage of pancreatic cancer and which received systemic chemotherapy with or without radiation. We report a 59-year-old man with a mass-forming lesion at the pancreatic head involving the common hepatic artery and portal vein, initially diagnosed as locally advanced pancreatic cancer and treated with chemoradiation therapy. After a month of continuous infusion of low dose 5-fluorouracil with concurrent local radiation (50.4 Gy), the pancreatic lesion diminished in size. However, the pancreatic body gradually enlarged and a capsule-like limb appeared in the following year. Serological markers and endoscopic retrograde cholangiopancreatography were compatible with those of AIP. No neoplastic tissue was identified on the fine needle aspiration biopsy of the pancreas. The pancreatic lesion responded well to steroid therapy and the patient remained in remission for one year after the withdrawal of steroids. Similar to pancreatic cancer, this current case of AIP responded to chemoradiation. Both serological and histological examinations were essential for images equivocal for either locally advanced pancreatic cancer or AIP.
authors.affiliation: Division of Endoscopy, Shizuoka Cancer Center, Shizuoka 411-8777, Japan. h.matsubayashi@scchr.jp
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Matsubayashi
authors.forename: Noriaki
authors.initials: N
authors.lastname: Hasuike
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Onozawa
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Kanemoto
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Ono
authors.forename: Ralph H
authors.initials: RH
authors.lastname: Hruban
mesh_terms: D001327:Autoimmune Diseases / Q000175:diagnosis / Q000628:therapy*; D059248:Chemoradiotherapy; D003951:Diagnostic Errors; D019160:Endosonography; D006801:Humans; D008297:Male; D008875:Middle Aged; D010190:Pancreatic Neoplasms / Q000175:diagnosis; D010195:Pancreatitis / Q000175:diagnosis / Q000628:therapy*