Case report of hypopituitarism with suspected syndrome of inappropriate VP secretion (SIADH) due to a large aneurysm of the internal carotid in the sellar region.

Hypopituitarism and hyponatremia, especially when severe, are infrequent findings particularly when the cause of hypopituitarism at presentation is unknown and untreated. Interestingly, hyponatremia is usually seen in elderly patients with hypopituitarism due to various causes. We present a case with unrecognized and untreated hypopituitarism due to a large aneurysm of the internal carotid artery in the sellar region causing the syndrome of inappropriate secretion of antidiuretic hormone (SIADH).