Endocrine Abstracts

Introduction: Hypophysary aneurysms are rare, they account for 1% to 2% of all intracranial aneurysms (1) and can be mistaken for pituitary adenomas, since they can have similar symptoms and even radiological signs especially if it’s an aneurysm completely thrombosed as angiography will show only avascular mass (2).

Clinical case: A 84 year old female with past medical history of hypertension, dyslipidemia and depressive disorder, presents to emergency room with vomits and somnolence, a brain CT Scan was performed that showed a hypophysary mass of 2×3,3 cm reported as pituitary macroadenoma vs Meningioma, and was discharged with a diagnosis of gastrointestinal infection. The patient missed the follow-up appointment to continue the study of the sellar mass. Tree years later she came back with anorexia, drowsiness, inespecific abdominal pain and hyponatremia. Physical exam was normal. Laboratory Test: Cr 0.73 mg/dl (0.60–1.00); Na 117 mmol/l (135–150); K 3.72 mmol/l (3.50–5.50); 241 mOsm/kg (285–295), TSH 0.137 microUI/ml (0.270–4.200), FT3 L 1.55 pg/ml (2.3–4.4), FT4 0.94 ng/dl (0.93–1.70) FSH 2.28 microUI/ml (3.35–21.63), LH 0.22 microUI/ml (2.80–21.70), Prolactin 65.93 ng/ml (1.20–30.00), IGF-I 40.33 ng/ml (17.00–200.00), Basal Cortisol 3.41 μg/dl (6.24–18.00) Synacthen Test (60 min) 18.45 μg/dl. Hypophysary MRI (contrast): Sellar lesion markedly hypointense in T2 sequence, with peripheral enhancement, heterogeneous signal in its interior, in continuity with left ICA, suggestive of aneurysmal malformation, with no remaining pituitary glandular. Cerebral Angiography: Giant saccular aneurysm dependent on the intracavernous left ICA, without mural thrombosis, of approximately 22.4×26.7×23 mm. Because of the high-risk surgery, a conservative management was approached. Replacement therapy was started with Hydrocortisone and Levothyroxine with improvement of the symptoms.

Conclusion: Hypopituitarism as result of an aneurysm extending into the sellar region is rare accounting for a prevalence of 0.17% (1) but it is important to kept in mind as differential diagnosis. Careful evaluation of the MRI and an angiogram should be considered for prevent unfortunate consequences in case surgery is an option

Reference: 1) Heshmati HM, et al. Hypopituitarism caused by intrasellar aneurysms. Mayo Clin Proc., 2001;76 (8):789–93.

2) Nguyen, Ha Son et al. A completely thrombosed, nongiant middle cerebral artery aneurysm mimicking an intra-axial neoplasm. Surgical neurology International, vol. 6 146. 7 Sep. 2015, doi:10.4103/2152-7806.164696.