title: Pancreatic cystic lesions with atypical steroid response should be carefully managed in cases of autoimmune pancreatitis.
abstract: OBJECTIVE
  Pancreatic cysts have been reported in cases with autoimmune pancreatitis (AIP) and are often treated by corticosteroid; however, their response to steroid has not been determined fully. We aimed to see the incidence and steroid response of pancreatic cysts and the features of cysts without proper response in cases with AIP.
  
  
  METHODS
  Fifty-eight AIP cases were analyzed for the incidence and associated factors of pancreatic cystic lesions (≥ 10 mm). Of these, 47 cases, determined for steroid response, were retrospectively investigated for the factors associated with cyst change by corticosteroid therapy.
  
  
  RESULTS
  At initial diagnosis, 17 pancreatic cystic lesions were recognized in 13 cases (22.4%) of AIP, with an average size of 30 mm (range: 11-130 mm), associated with higher incidence of elevated serum amylase (38.5% vs 11.1%, P = 0.02). Of these 13 cases, nine cases with 10 cystic lesions underwent steroid therapy in our hospital. All of seven unilocular cysts were dramatically shrunken or vanished in a few months; meanwhile, three cases with multilocular cysts showed scarcely any steroid response (P = 0.008). Of these three cases, two cases were revealed to accompany pancreatic ductal carcinoma, in contrast to null of seven unilocular cysts (P = 0.07).
  
  
  CONCLUSIONS
  Pancreatic cystic lesions are sometimes recognized in cases with AIP, and most unilocular cysts can be minimized by corticosteroids. However, clinicians must be alert for atypical pancreatic cysts, such as multilocular cysts or cysts without obvious steroid response.
authors.affiliation: Division of Endoscopy, Shizuoka Cancer Center, Shizuoka, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Matsubayashi
authors.affiliation: Division of Endoscopy, Shizuoka Cancer Center, Shizuoka, Japan.
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Iwai
authors.affiliation: Division of Endoscopy, Shizuoka Cancer Center, Shizuoka, Japan.
authors.forename: Toru
authors.initials: T
authors.lastname: Matsui
authors.affiliation: Division of Endoscopy, Shizuoka Cancer Center, Shizuoka, Japan.
authors.forename: Takuya
authors.initials: T
authors.lastname: Wada
authors.affiliation: Division of Endoscopy, Shizuoka Cancer Center, Shizuoka, Japan.
authors.forename: Noboru
authors.initials: N
authors.lastname: Kawata
authors.affiliation: Division of Diagnostic Radiology, Shizuoka Cancer Center, Shizuoka, Japan.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Ito
authors.affiliation: Division of Pathology, Shizuoka Cancer Center, Shizuoka, Japan.
authors.forename: Keiko
authors.initials: K
authors.lastname: Sasaki
authors.affiliation: Division of Hepato-Biliary-Pancreatic Surgery, Shizuoka Cancer Center, Shizuoka, Japan.
authors.forename: Katsuhiko
authors.initials: K
authors.lastname: Uesaka
authors.affiliation: Division of Endoscopy, Shizuoka Cancer Center, Shizuoka, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Ono
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000681:Amylases / Q000097:blood; D001327:Autoimmune Diseases / Q000150:complications*; D005260:Female; D005938:Glucocorticoids / Q000008:administration & dosage / Q000627:therapeutic use*; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D010181:Pancreatic Cyst / Q000188:drug therapy* / Q000453:epidemiology / Q000209:etiology* / Q000473:pathology; D010195:Pancreatitis / Q000150:complications*; D012189:Retrospective Studies; D016896:Treatment Outcome
chemical_list: D005938:Glucocorticoids; D000681:Amylases
keywords: autoimmune pancreatitis; corticosteroid; differential diagnosis; pancreatic cancer; pancreatic cyst