title: Spectrum of different types of hypophysitis: a clinicopathologic study of hypophysitis in 31 cases.
abstract: Hypophysitis has been histologically classified into five types: lymphocytic hypophysitis (LYH), granulomatous hypophysitis (GRH), xanthogranulomatous hypophysitis (XGH), xanthomatous hypophysitis (XH), and necrotizing hypophysitis. The present study evaluated 31 cases of hypophysitis to clarify their characteristic clinicopathologic features. The lesions were histologically classified into four groups: LYH (22 cases) including lymphocytic adenohypophysitis (LAH) (19 cases) and lymphocytic infundibuloneurohypophysitis (LINH) (3 cases), GRH (5 cases), XGH (2 cases), and XH (2 cases). In each group, the pituitary gland showed lymphocytic infiltration associated with focal or diffuse hypophysial destruction of variable severity and fibrosis. Histologic and clinical overlap among different types of hypophysitis, especially between LAH and LINH, suggest that these entities may have similar etiologic background and/or represent different stages of the same lesion. Considering the sampling sites and clinical manifestations, LAH may not usually involve the neurohypophysis, but LINH may often extend to the adenohypophysitis. A selective loss of adrenocorticotropic hormone-positive cells was seen in two patients with LAH despite only very slight lymphoplasmacytic infiltration. This suggests that there may be at least two causative mechanisms for hypopituitarism in hypophysitis: nonspecific destruction of all types of adenohypophysial cells by severe inflammation and selective destruction of specific adenohypophysial cells.
authors.affiliation: Department of Pathology, University of Tokushima School of Medicine, Tokushima, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Tashiro
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Sano
authors.forename: Bing
authors.initials: B
authors.lastname: Xu
authors.forename: Shing
authors.initials: S
authors.lastname: Wakatsuki
authors.forename: Noriko
authors.initials: N
authors.lastname: Kagawa
authors.forename: Hroshi
authors.initials: H
authors.lastname: Nishioka
authors.forename: Shozo
authors.initials: S
authors.lastname: Yamada
authors.forename: Kalman
authors.initials: K
authors.lastname: Kovacs
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D005355:Fibrosis / Q000473:pathology; D006801:Humans; D007249:Inflammation / Q000145:classification / Q000209:etiology / Q000473:pathology*; D008214:Lymphocytes / Q000473:pathology; D008297:Male; D008875:Middle Aged; D010900:Pituitary Diseases / Q000145:classification / Q000209:etiology / Q000473:pathology*; D010903:Pituitary Gland, Anterior / Q000473:pathology*; D010904:Pituitary Gland, Posterior / Q000473:pathology*; D011247:Pregnancy