An unusual presentation of hypopituitarism caused by a sellar aneurysm.

Hypopituitarism is a rare clinical condition that can present as a partial or complete absence of pituitary hormones. Hypopituitarism is most commonly caused by a sellar or parasellar mass, particularly a tumor, and the gold standard for its differential diagnosis is magnetic resonance imaging (MRI). Intrasellar aneurysm is an unusual cause of hypopituitarism. Indeed, about 0.17% of all cases of hypopituitarism are due to intrasellar aneurysms. We report the case of a 72-year-old man who was admitted to the hospital due to gastrointestinal symptoms and malnourishment. Due to persistent hyponatremia and spontaneous hypoglycemia in laboratory findings, the examination of the hypothalamic-pituitary-adrenal axis was eventually initiated, and the patient was later diagnosed with an unruptured aneurysm of the ophthalmic segment of the right internal carotid artery with sellar extension as a cause of panhypopituitarism. A combined endovascular treatment was performed with stent-assisted coil embolization of the aneurysm, and the patient was prescribed oral hormonal therapy. At the 1-year follow-up visit, no improvement in pituitary function was observed, and a pituitary MRI showed complete aneurysm occlusion and partial empty sella with significantly decreased pituitary volume. Aneurysms of the internal carotid artery are rare and may be associated with hypopituitarism and delayed diagnosis due to their unusual clinical presentation. Endovascular procedures, such as coil embolization of the aneurysm, could be the treatment of choice in these patients. Persistent hypopituitarism may occur even after successful treatment of the aneurysm.