Endocrine Abstracts

Background: Empty Sella syndrome (ESS) is caused by the herniation of the subarachnoid space into the sella turcica, causing compression of the pituitary gland. Patients may be asymptomatic or exhibit different degrees of pituitary hormone deficiency. Pan-hypopituitarism can occur if there is decreased or absent secretion of all of the anterior pituitary hormones.

Case: We report the case of a 68 year old female of Pakistani background who was visiting the UK. She presented with a 2 day history of lethargy. She reported feeling this way thrice during the last 5 years when her sodium levels were found to be low. Her past medical history included hypertension, renal stones and chronic hyponatraemia. Blood pressure was 157/70 mmHg. Clinical examination was unremarkable, with visual fields full to confrontation.

Investigations: Sodium 119 mmol/l (133–146). Paired Osmolalities: Serum Osmolality 258 mOsm/kgH2O (275–295), Urine Osmolality 339 mOsm/kgH2O, Urine Sodium 139 mmol/l. 9am cortisol 61 nmol/l (185–624). Short Synacthen test: 30 minute Cortisol 207 nmol/l, 60 minute Cortisol 256.80 nmol/l. ACTH – Outstanding. Serum Glucose 6.4 mmol/l (18 1.5–5.4). CT Head – Enlarged fluid-filled pituitary fossa. Anterior Pituitary Hormone testing: Prolactin 45 mIU/l (58–416), LH 0.3 I.U./l (>16), FSH 1.9 I.U./l (>30), IGF-1 3.8 nmol/l (4.8–21.6), TSH 1.57 mIU/l (0.30–4.8). TFTS: Free T4 < 3.2 pmol/l (7.7–20.6), Free T3 3.3 pmol/l (4.2–6.9). MRI Pituitary – empty sella with no fat or tumour seen within the pituitary fossa and normal enhancement of pituitary stalk.

Treatment: As the available anterior pituitary hormone levels were low we suspected pan-hypopituitarism. She was initiated on Hydrocortisone, and Levothyroxine replacement as her free T4 level was undetectable. Her sodium level improved from 119 mmol/l to 131 mmol/l over 4 days and her symptoms completely resolved. She was discharged on Hydrocortisone (10 mg – am and 5 mg – pm) and Levothyroxine (50 mcg). ACTH level later returned as 18 ng/l. She was referred for Ophthalmology review. As she returned to Pakistan, we advised her next of kin that she contact her local doctor for follow up, including repeat thyroid function testing.

Conclusion: This is an interesting case as this post-menopausal lady had suffered from chronic hyponatraemia due to pan-hypopituitarism associated with empty sella syndrome. Her sodium levels improved and symptoms resolved after hormone replacement was initiated.