title: Autoimmune pancreatitis mimicking pancreatic cancer.
abstract: OBJECTIVE
  Autoimmune pancreatitis (AIP) is a form of chronic pancreatitis that can often be difficult to distinguish from pancreatic cancer. We describe the clinical and radiographic features of 23 patients with AIP whose presentations mimicked pancreatic cancer.
  
  
  METHODS
  A review of clinic, radiology, and endoscopy records from a 6-year period identified patients with AIP initially suspected of having pancreatic cancer. Abdominal computed tomography (CT) with intravenous contrast, endoscopic ultrasonography (EUS), and/or ERCP was performed in each patient. The diagnosis of AIP was made histologically and/or cytologically for each patient.
  
  
  RESULTS
  Nineteen of 23 patients (83%) presented with new-onset weight loss, jaundice, or both. Nineteen (83%) patients had CT findings worrisome for pancreatic cancer including: (1) pancreatic enlargement or focal mass, (2) regional lymphadenopathy, and/or (3) vascular invasion. Eighteen patients (78%) had common bile duct strictures on ERCP. EUS-guided fine-needle aspiration biopsies excluded pancreatic cancer in all 22 patients who had EUS (96%). Seven patients had surgery for continued suspicion of pancreatic cancer.
  
  
  CONCLUSIONS
  Although AIP commonly presents with features suggestive of pancreatic cancer, clinical recognition of AIP with appropriate diagnostic testing including EUS with fine-needle aspiration, ERCP, IgG4 levels, and pancreatic protocol CT expedites diagnosis and can spare patients unnecessary surgery.
authors.affiliation: Division of Gastroenterology and Hepatology, Department of Medicine, Pancreaticobiliary Center, The University of Alabama at Birmingham, 1808 7th Ave S, BDB 380, Birmingham, AL 35294, USA.
authors.forename: Lindsay S
authors.initials: LS
authors.lastname: Robison
authors.forename: Cheri L
authors.initials: CL
authors.lastname: Canon
authors.forename: Shyam
authors.initials: S
authors.lastname: Varadarajulu
authors.forename: Mohamad A
authors.initials: MA
authors.lastname: Eloubeidi
authors.forename: Selwyn
authors.initials: S
authors.lastname: Vickers
authors.forename: C
authors.initials: C
authors.lastname: Mel Wilcox
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001327:Autoimmune Diseases / Q000175:diagnosis* / Q000276:immunology; D044963:Biopsy, Fine-Needle; D002760:Cholangiopancreatography, Endoscopic Retrograde; D003937:Diagnosis, Differential; D019160:Endosonography; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology; D008297:Male; D008875:Middle Aged; D010179:Pancreas / Q000000981:diagnostic imaging / Q000473:pathology / Q000648:ultrastructure; D010190:Pancreatic Neoplasms / Q000175:diagnosis* / Q000276:immunology; D010195:Pancreatitis / Q000175:diagnosis* / Q000276:immunology; D011446:Prospective Studies; D014057:Tomography, X-Ray Computed; D055815:Young Adult
chemical_list: D007074:Immunoglobulin G