[Severe hyponatremia disclosing adenohypophyseal insufficiency with empty sella syndrome]

We report a case of extremely severe hyponatraemia which led to the discovery of anterior hypophysis insufficiency associated with empty sella turcica in a dysimmune context. This type of hyponatraemia is consecutive to corticotropic and thyreo-tropic hormones deficiency and to inappropriate secretion of arginine vasopressin. These endocrine abnormalities are of suprapituitary origin. They can be explained by a hypothalamo-hypophyseal dysregulation of little known mechanism, or by a lesion of the hypothalamus.