title: Autoimmune pancreatitis and biliary intraepithelial neoplasia of the common bile duct: a case with diagnostically challenging but pathogenetically significant association.
abstract: Autoimmune pancreatitis (AIP) (also called IgG4-related sclerosing pancreatitis (IgG4-SP)) and IgG4-related sclerosing cholangitis (IgG4-SC) are frequently associated with each other. It is generally believed that association of these diseases with pancreatobiliary malignancy is, however, rare. Here, we report on the case of a patient with AIP whose biliary cytology revealed severely atypical cells. Surgically resected specimens from this patient showed typical AIP with IgG4-SC, as well as a mildly elevated lesion in the common bile duct with varying degrees of cellular atypia. In addition, the atypical cells tested positive for the mucin-core protein, MUC5AC and p53 overexpression. These findings led us to diagnose the common bile duct lesion as biliary intraepithelial neoplasia (BilIN, mainly BilIN-1/2). Recently, associations between K-ras mutations and pancreatobiliary carcinoma have been reported in patients with AIP. This case, therefore, provides important new insight into the potential association of AIP and/or IgG4-SC with malignancy (or precursor lesions) of the pancreatobiliary system.
authors.affiliation: Department of Pathology, Mito Medical Center, National Hospital Organization, Ibaraki, Japan. hohtani@mito.hosp.go.jp
authors.forename: Haruo
authors.initials: H
authors.lastname: Ohtani
authors.forename: Hiroyasu
authors.initials: H
authors.lastname: Ishida
authors.forename: Yuka
authors.initials: Y
authors.lastname: Ito
authors.forename: Takashi
authors.initials: T
authors.lastname: Yamaguchi
authors.forename: Masanori
authors.initials: M
authors.lastname: Koizumi
mesh_terms: D000230:Adenocarcinoma / Q000150:complications / Q000175:diagnosis* / Q000378:metabolism; D001327:Autoimmune Diseases / Q000150:complications / Q000175:diagnosis* / Q000378:metabolism; D014408:Biomarkers, Tumor / Q000378:metabolism; D015209:Cholangitis, Sclerosing / Q000150:complications / Q000175:diagnosis* / Q000378:metabolism; D003135:Common Bile Duct / Q000378:metabolism / Q000473:pathology* / Q000601:surgery; D003138:Common Bile Duct Neoplasms / Q000150:complications / Q000175:diagnosis* / Q000378:metabolism; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D008297:Male; D008875:Middle Aged; D055271:Mucin 5AC / Q000378:metabolism; D014057:Tomography, X-Ray Computed; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism
chemical_list: D014408:Biomarkers, Tumor; D007074:Immunoglobulin G; C524678:MUC5AC protein, human; D055271:Mucin 5AC; D016159:Tumor Suppressor Protein p53