A case of lymphocytic hypophysitis with masked diabetes insipidus unveiled by glucocorticoid replacement.
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.
Huang
Chun-Hao
CH
Department of Medicine, Division of Nephrology, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan.
Chou
Kang-Ju
KJ
Lee
Po-Tsang
PT
Chen
Chien-Liang
CL
Chung
Hsiao-Ming
HM
Fang
Hua-Chang
HC
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*
D005938:Glucocorticoids