PITUITARY ADENOMA ASSOCIATED WITH INAPPROPRIATE ANTIDIURETIC HORMONE SECRETION

Abstract

ABSTRACT A 50 year old male with a chromophobe adenoma with suprasellar extension manifested hyponatraemia, plasma hypoosmolality, renal salt wasting and inability to excrete dilute urine after a standard water load. The patient exhibited no evidence of thyroid or adrenal insufficiency. The inability to excrete a water load was not corrected by prior cortisone administration but was partially corrected after ethanol ingestion. A measurable inappropriate amount of arginine vasopressin was excreted in the presence of sustained hydration. It is suggested that inappropriate production of antidiuretic hormone either by the adenoma, or secondary to hypothalamic involvement by the suprasellar extension of the tumour was responsible for the observed findings.