title: Endoscopic ultrasound-guided fine needle aspiration in the differentiation of type 1 and type 2 autoimmune pancreatitis.
abstract: OBJECTIVE
  To investigate the usefulness of endoscopic ultra-sound-guided fine needle aspiration (EUS-FNA) in the differentiation of autoimmune pancreatitis (AIP).
  
  
  METHODS
  We retrospectively reviewed 47 of 56 AIP patients who underwent EUS-FNA and met the Asian diagnostic criteria. On 47 EUS-FNA specimens, we evaluated the presence of adequate material and characteristic features of lymphoplasmacytic sclerosing pancreatitis (LPSP) and idiopathic duct-centric pancreatitis (IDCP) mentioned in the International Consensus Diagnostic Criteria and examined if these findings make a contribution to the differential diagnosis of type 1 and type 2 AIP. A disposable 22-gauge needle was used for EUS-FNA.
  
  
  RESULTS
  Adequate specimens including pancreatic tissue for differentiating AIP from cancer were obtained from 43 of 47 patients who underwent EUS-FNA. EUS-FNA was performed from the pancreatic head in 21 cases, which is known to be technically difficult when performed by core biopsy; there was no significant difference in the results compared with pancreatic body-tail. Nine of 47 patients met level 1 findings of LPSP and 5 patients met level 2 findings of LPSP. No one met level 1 findings of IDCP, but 3 patients met level 2 findings of IDCP. Of 10 seronegative cases, 2 cases were diagnosed with "definitive type 1 AIP", and 3 cases were diagnosed with "probable type 2 AIP" when considering both the level 2 histological findings and response to steroids.
  
  
  CONCLUSIONS
  EUS-FNA is useful in the differentiation of type 1 and type 2 AIP, particularly in seronegative cases.
authors.affiliation: Department of Gastroenterology, Nagoya University Graduate School of Medicine, 65 Tsuruma-cho, Showa-ku, Nagoya, Japan.
authors.forename: Takuya
authors.initials: T
authors.lastname: Ishikawa
authors.forename: Akihiro
authors.initials: A
authors.lastname: Itoh
authors.forename: Hiroki
authors.initials: H
authors.lastname: Kawashima
authors.forename: Eizaburo
authors.initials: E
authors.lastname: Ohno
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Matsubara
authors.forename: Yuya
authors.initials: Y
authors.lastname: Itoh
authors.forename: Yosuke
authors.initials: Y
authors.lastname: Nakamura
authors.forename: Takeshi
authors.initials: T
authors.lastname: Hiramatsu
authors.forename: Masanao
authors.initials: M
authors.lastname: Nakamura
authors.forename: Ryoji
authors.initials: R
authors.lastname: Miyahara
authors.forename: Naoki
authors.initials: N
authors.lastname: Ohmiya
authors.forename: Hidemi
authors.initials: H
authors.lastname: Goto
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Hirooka
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001327:Autoimmune Diseases / Q000145:classification / Q000175:diagnosis* / Q000276:immunology; D003937:Diagnosis, Differential; D061765:Endoscopic Ultrasound-Guided Fine Needle Aspiration; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010195:Pancreatitis / Q000145:classification / Q000175:diagnosis* / Q000276:immunology; D012189:Retrospective Studies