title: Corticosteroid-responsive pancreatic cyst found in autoimmune pancreatitis.
abstract: There have been only a few reports of autoimmune pancreatitis complicated with pancreatic cyst and such cysts are rare, probably due to the absence of severe tissue necrosis and/or lack of stasis of the pancreatic juice in this condition. However, during a follow-up of 48 patients with this disease, we found 3 patients with pancreatic cysts, and this enabled us to evaluate their clinicopathological findings. Between September 1994 and July 2003, we treated and followed 48 patients with autoimmune pancreatitis, and found 3 patients with pancreatic cyst formation that was responsive to corticosteroid therapy. All of the patients with cysts had high serum IgG4 concentrations. After corticosteroid therapy, rapid resolution of the pancreatic cysts was observed. Immunostaining with goat polyclonal antibody for each IgG subclass showed severe infiltration of IgG4-positive plasma cells in the cyst wall in one patient. The high serum IgG4 concentration and favorable response to corticosteroid therapy suggests that a highly active state of the inflammatory process is closely associated with cyst formation, and that a corticosteroid-responsive pancreatic cyst is a characteristic feature of autoimmune pancreatitis.
authors.affiliation: Department of Medicine, Gastroenterology, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto, 390-8621, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Muraki
authors.forename: Hideaki
authors.initials: H
authors.lastname: Hamano
authors.forename: Yasuhide
authors.initials: Y
authors.lastname: Ochi
authors.forename: Norikazu
authors.initials: N
authors.lastname: Arakura
authors.forename: Mari
authors.initials: M
authors.lastname: Takayama
authors.forename: Kenichi
authors.initials: K
authors.lastname: Komatsu
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Komiyama
authors.forename: Shigeyuki
authors.initials: S
authors.lastname: Kawa
authors.forename: Takeshi
authors.initials: T
authors.lastname: Uehara
authors.forename: Kendo
authors.initials: K
authors.lastname: Kiyosawa
mesh_terms: D000974:Antibodies, Antinuclear / Q000032:analysis / Q000276:immunology; D001327:Autoimmune Diseases / Q000150:complications / Q000175:diagnosis / Q000276:immunology*; D001707:Biopsy, Needle; D002760:Cholangiopancreatography, Endoscopic Retrograde / Q000379:methods; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007074:Immunoglobulin G / Q000032:analysis / Q000276:immunology; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D010181:Pancreatic Cyst / Q000150:complications / Q000188:drug therapy* / Q000473:pathology; D010186:Pancreatic Function Tests; D010195:Pancreatitis / Q000150:complications / Q000276:immunology* / Q000473:pathology; D011239:Prednisolone / Q000627:therapeutic use*; D018570:Risk Assessment; D012494:Sampling Studies; D012720:Severity of Illness Index; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
chemical_list: D000974:Antibodies, Antinuclear; D007074:Immunoglobulin G; D011239:Prednisolone