title: IgG4-related hypophysitis is highly prevalent among cases of histologically confirmed hypophysitis.
abstract: IgG4-related disease is an immune-mediated disease with manifestations in most organ systems among them the pituitary gland. To date, few cases of histologically confirmed cases of IgG-related hypophysitis have been reported. The aim of this study was to retrospectively determine the prevalence of IgG4-related hypophysitis among cases previously diagnosed as primary hypophysitis (lymphocytic hypophysitis, granulomatous hypophysitis and hypophysitis not otherwise specified). Histological and immunohistochemical analysis revealed that 12 of 29 cases (41.4%) previously diagnosed as primary hypophysitis fulfilled the criteria for IgG4-related disease and, thus, IgG4-related hypophysitis should always be considered in the differential diagnosis of primary hypophysitis. All cases of IgG4-related hypophysitis showed a dense lymphoplasmacytic infiltrate with more than 10 IgG4-positive cells per high power field and a ratio of IgG4/IgG-positive cells of more than 40%, whereas storiform fibrosis was an inconsistent histological feature and was also seen in few cases of non-IgG-related hypophysitis, thus lacking sensitivity and specificity. Obliterative phlebitis was not seen in any case. Thus, histological criteria defined for IgG4-related disease in other organs should be modified for IgG4-related hypophysitis, accordingly.
authors.affiliation: Institute of Neuropathology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Bernreuther
authors.affiliation: Department of Pathology, Karolinska Institute and University Hospital, Stockholm, Sweden.
authors.forename: Christopher
authors.initials: C
authors.lastname: Illies
authors.affiliation: Department of Neurosurgery, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
authors.forename: Jörg
authors.initials: J
authors.lastname: Flitsch
authors.affiliation: Department of Neurosurgery, University of Erlangen-Nürnberg, Erlangen, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Buchfelder
authors.affiliation: Institute of Neuropathology, Friedrich-Alexander University Erlangen-Nürnberg (FAU), Erlangen, Germany.
authors.forename: Rolf
authors.initials: R
authors.lastname: Buslei
authors.affiliation: Institute of Neuropathology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
authors.forename: Markus
authors.initials: M
authors.lastname: Glatzel
authors.affiliation: Institute of Neuropathology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Saeger
mesh_terms: D000368:Aged; D000069281:Autoimmune Hypophysitis / Q000209:etiology / Q000473:pathology*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D000072659:Hypophysitis / Q000473:pathology*; D007018:Hypopituitarism; D007074:Immunoglobulin G; D008297:Male; D010902:Pituitary Gland; D010950:Plasma Cells / Q000473:pathology; D015995:Prevalence
chemical_list: D007074:Immunoglobulin G
keywords: IgG4; histological criteria; hypophysitis; prevalence