title: A case of lymphocytic hypophysitis with masked diabetes insipidus unveiled by glucocorticoid replacement.
abstract: Lymphocytic hypophysitis may involve the pituitary gland and various hormonal abnormalities. A 72-year-old man presented with euvolemic hyponatremia caused by glucocorticoid deficiency. After glucocorticoid replacement, hypernatremia in the presence of dilute urine was found. Central diabetes insipidus (DI) was confirmed later by a significant increase in urine osmolality after vasopressin administration. Brain magnetic resonance imaging showed a pituitary mass and loss of hyperintense signal in the posterior pituitary gland on T1-weighted imaging. The patient underwent a transsphenoidal adenectomy, and pathological examination of dissected tissues showed a typical finding of lymphocytic hypophysitis. Two months after surgery, the patient's central DI had resolved sufficiently that 1-desamino-8- d -arginine vasopressin therapy was discontinued without polyuria. However, he was kept on glucocorticoid and levothyroxine therapy. In conclusion, lymphocytic hypophysitis may feature a concealed central DI caused by glucocorticoid deficiency-associated hyponatremia.
authors.affiliation: Department of Medicine, Division of Nephrology, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan.
authors.forename: Chun-Hao
authors.initials: CH
authors.lastname: Huang
authors.forename: Kang-Ju
authors.initials: KJ
authors.lastname: Chou
authors.forename: Po-Tsang
authors.initials: PT
authors.lastname: Lee
authors.forename: Chien-Liang
authors.initials: CL
authors.lastname: Chen
authors.forename: Hsiao-Ming
authors.initials: HM
authors.lastname: Chung
authors.forename: Hua-Chang
authors.initials: HC
authors.lastname: Fang
mesh_terms: D000368:Aged; D003919:Diabetes Insipidus / Q000175:diagnosis*; D005938:Glucocorticoids / Q000378:metabolism*; D020249:Hormone Replacement Therapy / Q000379:methods*; D006801:Humans; D008214:Lymphocytes / Q000473:pathology*; D008218:Lymphocytosis / Q000473:pathology*; D008297:Male; D010900:Pituitary Diseases / Q000175:diagnosis*; D010902:Pituitary Gland / Q000473:pathology*
chemical_list: D005938:Glucocorticoids