Two Cases of Hypopituitarism Caused by Intrasellar Aneurysm.

Giant internal carotid artery aneurysms sometimes extend into the sellar region, which rarely but occasionally results in hypopituitarism due to the compression of the normal pituitary gland or hypothalamus. Hyponatremia is a known complication of hypopituitarism. We herein report two cases of hypopituitarism caused by intrasellar aneurysm of different origins, resulting in hyponatremia. Untreated hypopituitarism may lead to lethargy, coma, cardiac arrhythmia, and death. Therefore, we must be alert for the occurrence of giant intrasellar aneurysm, as it causes hypopituitarism. The prompt diagnosis and treatment of hypopituitarism are necessary to prevent this fatal outcome.