Hypopituitarism caused by intrasellar aneurysms

Objective: To determine the prevalence, clinical presentation, and outcome of hypopituitarism due to an intrasellar aneurysm. Patients and Methods: We performed a retrospective review of Mayo Clinic, R ochester, Minn, medical records from 1950 through 1995. We calculated the p revalence of hypopituitarism, characterized the clinical presentation, and evaluated postoperative outcomes. Results: Of 4087 patients with a diagnosis of hypopituitarism, 7 had hypopi tuitarism due to an intrasellar aneurysm, accounting for a prevalence of 0. 17%. Adrenal, thyroid, and gonadal deficiencies were observed in 7, 6, and 5 patients, respectively. The prolactin level was increased in the 2 patien ts in whom it was measured. No patient had diabetes insipidus. All had visu al impairment. In 5 patients an intrasellar aneurysm of the internal caroti d artery was diagnosed preoperatively based on 1 or more imaging procedures . In the other 2 patients (1 with an internal carotid artery aneurysm and 1 with an anterior cerebral artery aneurysm), the diagnosis was made at surg ical exploration. Four patients underwent a surgical procedure: 2 had direc t packing of the aneurysm, and 2 had a bypass with proximal carotid occlusi on or aneurysm trapping. Pituitary function remained unchanged postoperativ ely. Conclusion: An intrasellar aneurysm is a rare cause of hypopituitarism (0.1 7% of cases). Preoperative diagnosis is essential for successful surgical o utcomes. Hypopituitarism is usually permanent.