title: IgG4-related disease of the rectum.
abstract: IgG4-related disease is a relatively new disease entity characterized by elevated serum IgG4 levels and marked infiltration of IgG4-positive plasma cells in lesions. Organ enlargement or nodular lesions consisting of abundant infiltration of lymphocytes and IgG4-positive plasma cells and fibrosis are seen in various organs throughout. We encountered a patient with an inflammatory pseudotumor of the rectum, which was histopathologically confirmed to be an IgG4-related disease. The patient was a 28-year-old woman who had constipation for 3 months. The endoluminal ultrasonography showed a lesion that was heterogeneous and low echogenic in lower rectum. The result of colonoscopic biopsy findings was of chronic proctitis with lymphoid aggregates. For a confirmative diagnosis, excision was performed. Histopathological examination represented plasma cell infiltration and fibrosis. Immunohistochemistry revealed prominence of IgG4-positive plasma cells and confirmed the diagnosis of IgG4-related disease. The patient is currently under observation on low-dose oral prednisolone without relapse.
authors.affiliation: Department of Surgery, Yeouido St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Sung-Bong
authors.initials: SB
authors.lastname: Choi
authors.affiliation: Department of Internal Medicine, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Chul-Hyun
authors.initials: CH
authors.lastname: Lim
authors.affiliation: Department of Surgery, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Myung-Guen
authors.initials: MG
authors.lastname: Cha
authors.affiliation: Department of Surgery, Yeouido St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Won-Kyung
authors.initials: WK
authors.lastname: Kang
keywords: Colonoscopy; Immunoglobulin G; Plasma cells; Rectum