title: Colovesical fistula caused by glucocorticoid therapy for IgG4-related intrapelvic mass.
abstract: IgG4-related disease (IgG4-RD) is an immune-mediated fibroinflammatory disorder that can occur in almost all systemic organs and generally responds to corticosteroid treatment. We report a rare case of an IgG4-related intrapelvic mass lesion that responded to steroid therapy but caused a fistula between the sigmoid colon and bladder. A 71-year-old man was followed after treatment for hepatocellular carcinoma. Follow-up computed tomography (CT) incidentally depicted left hydronephrosis with an ill-demarcated intrapelvic mass lesion. This lesion was histologically diagnosed as IgG4-RD by open biopsy, and peroral steroid therapy was initiated. One month after starting steroids, a colovesical fistula was detected by follow-up CT. A colostomy and urethral catheterization were emergently performed. The patient recovered and the mass lesion was drastically minimized by the initiation of glucocorticoids; however, he still needs urethral catheterization. IgG4-RD develops in various systemic organs and generally responds well to steroids. Clinicians must be watchful for the complications of responses to corticosteroids, such as fistulization, when the mass lesion of IgG4-RD is adjacent to multiple luminal organs.
authors.affiliation: Yohei Yabuuchi, Hiroyuki Matsubayashi, Hiroyuki Ono, Division of Endoscopy, Shizuoka Cancer Center, Suntogun, Shizuoka 411-8777, Japan.
authors.forename: Yohei
authors.initials: Y
authors.lastname: Yabuuchi
authors.affiliation: Yohei Yabuuchi, Hiroyuki Matsubayashi, Hiroyuki Ono, Division of Endoscopy, Shizuoka Cancer Center, Suntogun, Shizuoka 411-8777, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Matsubayashi
authors.affiliation: Yohei Yabuuchi, Hiroyuki Matsubayashi, Hiroyuki Ono, Division of Endoscopy, Shizuoka Cancer Center, Suntogun, Shizuoka 411-8777, Japan.
authors.forename: Masato
authors.initials: M
authors.lastname: Matsuzaki
authors.affiliation: Yohei Yabuuchi, Hiroyuki Matsubayashi, Hiroyuki Ono, Division of Endoscopy, Shizuoka Cancer Center, Suntogun, Shizuoka 411-8777, Japan.
authors.forename: Akio
authors.initials: A
authors.lastname: Shiomi
authors.affiliation: Yohei Yabuuchi, Hiroyuki Matsubayashi, Hiroyuki Ono, Division of Endoscopy, Shizuoka Cancer Center, Suntogun, Shizuoka 411-8777, Japan.
authors.forename: Michihisa
authors.initials: M
authors.lastname: Moriguchi
authors.affiliation: Yohei Yabuuchi, Hiroyuki Matsubayashi, Hiroyuki Ono, Division of Endoscopy, Shizuoka Cancer Center, Suntogun, Shizuoka 411-8777, Japan.
authors.forename: Ichiro
authors.initials: I
authors.lastname: Kawamura
authors.affiliation: Yohei Yabuuchi, Hiroyuki Matsubayashi, Hiroyuki Ono, Division of Endoscopy, Shizuoka Cancer Center, Suntogun, Shizuoka 411-8777, Japan.
authors.forename: Ichiro
authors.initials: I
authors.lastname: Ito
authors.affiliation: Yohei Yabuuchi, Hiroyuki Matsubayashi, Hiroyuki Ono, Division of Endoscopy, Shizuoka Cancer Center, Suntogun, Shizuoka 411-8777, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Ono
keywords: Colostomy; Colovesical fistula; IgG4-related disease; Intrapelvic mass; Steroid therapy; Urethral catheterization