title: A focal mass-forming autoimmune pancreatitis mimicking pancreatic cancer with obstruction of the main pancreatic duct.
abstract: BACKGROUND
  Autoimmune pancreatitis (AIP) is a rare disease that closely mimics pancreatic cancer (PC) in its presentation. It is very important for clinicians to distinguish one from the other because their treatment and prognosis are vastly different. Typical radiological imaging findings, in particular observation of diffusely or segmentally narrowed main pancreatic duct (MPD) with an irregular wall by endoscopic retrograde cholangiopancreatography (ERCP), are essential for making the diagnosis of AIP. On the other hand, MPD obstruction is one of the most frequent features on ERCP.
  
  
  METHODS
  We report a rare case of a patient with focal mass-forming AIP strongly suspected of being PC because of MPD obstruction on ERCP.
  
  
  CONCLUSIONS
  It was difficult to distinguish PC from AIP with current diagnostic modalities. We will continue to make an effort to distinguish between the two disorders to prevent unnecessary surgery.
authors.affiliation: Division of Hepato-Biliary-Pancreatic Surgery, Department of Surgery, Kobe University Graduate School of Medicine, 7-5-2 Kusunoki-Cho, Chuo-Ku, Kobe, 650-0017, Japan. imatsu@med.kobe-u.ac.jp
authors.forename: Ippei
authors.initials: I
authors.lastname: Matsumoto
authors.forename: Makoto
authors.initials: M
authors.lastname: Shinzeki
authors.forename: Hirochika
authors.initials: H
authors.lastname: Toyama
authors.forename: Sadaki
authors.initials: S
authors.lastname: Asari
authors.forename: Tadahiro
authors.initials: T
authors.lastname: Goto
authors.forename: Isamu
authors.initials: I
authors.lastname: Yamada
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Ajiki
authors.forename: Takumi
authors.initials: T
authors.lastname: Fukumoto
authors.forename: Yonson
authors.initials: Y
authors.lastname: Ku
mesh_terms: D000368:Aged; D001327:Autoimmune Diseases / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000601:surgery; D002760:Cholangiopancreatography, Endoscopic Retrograde; D003937:Diagnosis, Differential; D006801:Humans; D008297:Male; D010183:Pancreatic Ducts / Q000473:pathology*; D010190:Pancreatic Neoplasms; D010195:Pancreatitis / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000601:surgery; D014057:Tomography, X-Ray Computed