title: A proposal for differentiation between early- and advanced-stage autoimmune pancreatitis by endoscopic ultrasonography.
abstract: OBJECTIVE
  We evaluated the characteristic endoscopic ultrasonography (EUS) findings of early autoimmune pancreatitis (AIP).
  
  
  METHODS
  Nineteen patients with AIP were identified from our database. We reviewed the following features of EUS as being potentially characteristic of early AIP: hyperechoic foci, hyperechoic strands, lobularity, hyperechoic pancreatic duct margins and reduced echogenicity. According to the Cambridge classification for chronic pancreatitis, we classified AIP into early AIP (Grades 0-2) and advanced AIP (Grades 3-5) and examined the histopathological findings in each stage of AIP.
  
  
  RESULTS
  There were nine cases of early AIP and 10 cases of advanced AIP. Five of the nine early cases of AIP showed spontaneous remission without corticosteroid therapy (P < 0.05). The EUS findings were as follows (early vs advanced): hyperechoic foci, 100% (9/9) vs 100% (10/10); hyperechoic strands, 66.7% (6/9) vs 70% (7/10); lobularity, 77.8% (7/9) vs 20% (2/10); hyperechoic pancreatic duct margin, 88.9% (8/9) vs 30% (3/10); reduced echogenicity, 88.9% (8/9) vs 90% (9/10). Lobularity and hyperechoic pancreatic duct margin were detected at a significantly higher frequency in early AIP than in the advanced AIP patients (P < 0.05). Regarding the histopathological findings, acinar cells were better preserved in the cases of early AIP, whereas acinar cells were reduced in number and replaced by massive fibrosis in the patients with advanced AIP.
  
  
  CONCLUSIONS
  Lobularity and hyperechoic pancreatic duct margin are characteristic EUS features of early AIP, which has a more favorable prognosis, and shows a higher frequency of spontaneous remission and preservation of acinar cells, than advanced AIP.
authors.affiliation: Division of Gastroenterology, Yokohama City University, Graduate School of Medicine, Yokohama, Japan. kubotak@yokohama-cu.ac.jp
authors.forename: Kensuke
authors.initials: K
authors.lastname: Kubota
authors.forename: Shingo
authors.initials: S
authors.lastname: Kato
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Akiyama
authors.forename: Koji
authors.initials: K
authors.lastname: Fujita
authors.forename: Masato
authors.initials: M
authors.lastname: Yoneda
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Takahashi
authors.forename: Masami
authors.initials: M
authors.lastname: Ogawa
authors.forename: Masahiko
authors.initials: M
authors.lastname: Inamori
authors.forename: Yasunobu
authors.initials: Y
authors.lastname: Abe
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Kirikoshi
authors.forename: Noritoshi
authors.initials: N
authors.lastname: Kobayashi
authors.forename: Satoru
authors.initials: S
authors.lastname: Saito
authors.forename: Kantaro
authors.initials: K
authors.lastname: Hisatomi
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Matsuhashi
authors.forename: Atsushi
authors.initials: A
authors.lastname: Nakajima
mesh_terms: D000368:Aged; D001327:Autoimmune Diseases / Q000000981:diagnostic imaging*; D019160:Endosonography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010183:Pancreatic Ducts / Q000000981:diagnostic imaging; D010195:Pancreatitis / Q000145:classification / Q000000981:diagnostic imaging*