title: Prospective multicenter study on the usefulness of EUS-guided FNA biopsy for the diagnosis of autoimmune pancreatitis.
abstract: OBJECTIVE
  In the International Consensus Diagnostic Criteria (ICDC), autoimmune pancreatitis (AIP) is classified into types 1 and 2, and its definite histopathology diagnosis can be made based only on surgical or core biopsy specimens. Although EUS-guided FNA (EUS-FNA) biopsy is a safe technique for the collection of pancreatic tissue, no consensus viewpoint has been reached with regard to the role of EUS-FNA biopsy in the diagnosis of AIP. This study investigated the utility of pancreatic tissue collected by EUS-FNA biopsy by using a standard 22-gauge aspiration needle in the diagnosis of AIP.
  
  
  METHODS
  Patients with suspected AIP were prospectively enrolled in Nagoya University Hospital and Nagoya University-affiliated institutions. Pancreatic tissue was collected from each by EUS-FNA biopsy with a standard 22-gauge aspiration needle.
  
  
  RESULTS
  Fifty patients were registered, including 45 with a final diagnosis of AIP. Lymphoplasmacytic infiltration and abundant immunoglobulin G4-positive plasmacyte infiltration (>10/high-power field) were detected in 36 (72%) and 27 (54%) patients, respectively. Obliterative phlebitis and storiform fibrosis were not detected in our study. Granulocytic epithelial lesions (GEL) were observed in 3 patients. The sensitivity, specificity, positive predictive value, and negative predictive value of EUS-FNA biopsy to definitively diagnose AIP were 7.9% (3/38), 100% (12/12), 100% (3/3), and 25.5% (12/47), respectively. Pathology evaluation of pancreatic tissue collected by EUS-FNA biopsy improved the diagnostic accuracy in 8 (16%) of the 50 patients.
  
  
  CONCLUSIONS
  In this study, EUS-FNA biopsy by using a standard 22-gauge aspiration needle is not an effective diagnostic method for most patients with AIP. The combination of level 2 histology diagnosis of AIP with other findings specified in the ICDC slightly improved the diagnostic accuracy, although it still remains insufficiently accurate for routine clinical use.(
  
  
  BACKGROUND
  000006297.).
authors.affiliation: Department of Gastroenterology and Hepatology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Tomomasa
authors.initials: T
authors.lastname: Morishima
authors.affiliation: Department of Gastroenterology and Hepatology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Kawashima
authors.affiliation: Department of Gastroenterology and Hepatology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Eizaburo
authors.initials: E
authors.lastname: Ohno
authors.affiliation: Department of Endoscopy, Nagoya, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Yamamura
authors.affiliation: Department of Endoscopy, Nagoya, Japan.
authors.forename: Kohei
authors.initials: K
authors.lastname: Funasaka
authors.affiliation: Department of Gastroenterology and Hepatology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Masanao
authors.initials: M
authors.lastname: Nakamura
authors.affiliation: Department of Gastroenterology and Hepatology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Ryoji
authors.initials: R
authors.lastname: Miyahara
authors.affiliation: Department of Gastroenterology and Hepatology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Osamu
authors.initials: O
authors.lastname: Watanabe
authors.affiliation: Department of Gastroenterology and Hepatology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Ishigami
authors.affiliation: Nagoya University Hospital Department of Pathology and Laboratory Medicine, Nagoya, Japan.
authors.forename: Yoshie
authors.initials: Y
authors.lastname: Shimoyama
authors.affiliation: Nagoya University Hospital Department of Pathology and Laboratory Medicine, Nagoya, Japan.
authors.forename: Shigeo
authors.initials: S
authors.lastname: Nakamura
authors.affiliation: Department of Liver, Biliary Tract and Pancreas Diseases, Fujita Health University, Toyoake, Japan.
authors.forename: Senju
authors.initials: S
authors.lastname: Hashimoto
authors.affiliation: Department of Gastroenterology and Hepatology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Hidemi
authors.initials: H
authors.lastname: Goto
authors.affiliation: Department of Endoscopy, Nagoya, Japan.
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Hirooka
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001327:Autoimmune Diseases / Q000175:diagnosis / Q000473:pathology*; D061765:Endoscopic Ultrasound-Guided Fine Needle Aspiration; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000378:metabolism; D008214:Lymphocytes / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D010195:Pancreatitis / Q000175:diagnosis / Q000473:pathology*; D010950:Plasma Cells / Q000378:metabolism / Q000473:pathology*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D055815:Young Adult
chemical_list: D007074:Immunoglobulin G