title: Inappropriate antidiuresis associated with pituitary adenoma--mechanisms not involving inappropriate secretion of vasopressin.
abstract: We report an unusual case of inappropriate antidiuresis with undetectable vasopressin in an elderly man presenting with confusion due to severe hyponatremia. Further investigations led to the diagnosis of non-functional pituitary macroadenoma. The patient had normal thyroid and adrenal function. The abnormal water balance resolved promptly after transsphenoidal removal of the tumor, confirmed by a repeat water loading test. We conclude that inappropriate antidiuresis in the absence of excess vasopressin secretion may implicate mass effect from an underlying pituitary tumor.
authors.affiliation: Department of Medicine, Veterans General Hospital-Taipei and School of Medicine, National Yang-Ming University, Taiwan.
authors.forename: S C
authors.initials: SC
authors.lastname: Hung
authors.forename: Y K
authors.initials: YK
authors.lastname: Wen
authors.forename: Y Y
authors.initials: YY
authors.lastname: Ng
authors.forename: W C
authors.initials: WC
authors.lastname: Yang
mesh_terms: D000236:Adenoma / Q000150:complications* / Q000503:physiopathology; D000368:Aged; D003221:Confusion / Q000209:etiology; D006801:Humans; D007010:Hyponatremia / Q000209:etiology; D007177:Inappropriate ADH Syndrome / Q000209:etiology* / Q000503:physiopathology; D008297:Male; D010911:Pituitary Neoplasms / Q000150:complications* / Q000503:physiopathology; D014667:Vasopressins / Q000378:metabolism*
chemical_list: D014667:Vasopressins