title: The clinical and radiological characteristics of focal mass-forming autoimmune pancreatitis: comparison with chronic pancreatitis and pancreatic cancer.
abstract: OBJECTIVE
  We investigated the clinical and radiological features of focal mass-forming autoimmune pancreatitis (FMF AIP) to help physicians avoid performing unnecessary surgery because of an improper diagnosis.
  
  
  METHODS
  We evaluated 23 patients with chronic inflammatory pancreatic masses and who underwent pancreatectomy for presumed pancreatic cancer from April 1995 to December 2005. These patients were distinguished into 8 FMF AIP patients and 15 ordinary chronic pancreatitis patients through a histological review, along with considering the immunoglobulin G4 staining. Twenty-six randomly selected pancreatic cancer patients were also evaluated as a control group.
  
  
  RESULTS
  On the portal venous phase of computed tomography, 6 (85.7%) of 7 FMF AIP patients showed homogeneous enhancement, whereas only 3 chronic pancreatitis patients (25%) and none of the pancreatic cancer patients showed homogeneous enhancement (P < 0.001). None of the FMF AIP patients showed upstream main pancreatic duct dilatation greater than 5 mm or proximal pancreatic atrophy.
  
  
  CONCLUSIONS
  For patients with a pancreatic mass, if their radiological images show homogeneous enhancement on the portal venous phase, the absence of significant upstream main pancreatic duct dilatation greater than 5 mm, and the absence of proximal pancreatic atrophy, then conducting further evaluations should be considered to avoid performing unnecessary surgery.
authors.affiliation: Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Woo Ik
authors.initials: WI
authors.lastname: Chang
authors.forename: Beom Jin
authors.initials: BJ
authors.lastname: Kim
authors.forename: Jong Kyun
authors.initials: JK
authors.lastname: Lee
authors.forename: Pung
authors.initials: P
authors.lastname: Kang
authors.forename: Kwang Hyuck
authors.initials: KH
authors.lastname: Lee
authors.forename: Kyu Taek
authors.initials: KT
authors.lastname: Lee
authors.forename: Jong Chul
authors.initials: JC
authors.lastname: Rhee
authors.forename: Kee-Taek
authors.initials: KT
authors.lastname: Jang
authors.forename: Seong Ho
authors.initials: SH
authors.lastname: Choi
authors.forename: Dong Wook
authors.initials: DW
authors.lastname: Choi
authors.forename: Dong Il
authors.initials: DI
authors.lastname: Choi
authors.forename: Jae Hoon
authors.initials: JH
authors.lastname: Lim
mesh_terms: D000368:Aged; D001327:Autoimmune Diseases / Q000175:diagnosis* / Q000276:immunology / Q000601:surgery; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology; D008297:Male; D008875:Middle Aged; D010179:Pancreas / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery; D010180:Pancreatectomy / Q000592:standards; D010190:Pancreatic Neoplasms / Q000175:diagnosis* / Q000601:surgery; D050500:Pancreatitis, Chronic / Q000175:diagnosis* / Q000276:immunology / Q000601:surgery; D014057:Tomography, X-Ray Computed
chemical_list: D007074:Immunoglobulin G