SUN-428 Neurosarcoidosis: A Rare Cause of Hypothalamic-Pituitary Dysfunction

Introduction: sarcoidosis is a granulomatous disease. About 5-15% of patients have central nervous system involvement (neurosarcoidosis) that might cause both anterior and posterior pituitary dysfunction with hypopituitarism and diabetes insipidus related to hypothalamic-pituitary axis involvement. Clinical case: a 44 year-old woman presented to the emergency room with a 3-months history of bilateral vision loss. She also complained of galactorrhea, oligomenorrhea, polydipsia (drinking 5L of water a day), polyuria and nocturia. A year before, she had been diagnosed a pulmonary interstitial disease, with no definite diagnosis at the time. Cranial MRI showed a midline mass addressing the anterior and posterior aspects of the sella turcica and dorsum sella, with hypothalamic and optic chiasma swelling, being the radiological findings suggestive of granulomatous disease. Analytic baseline tests revealed a sodium 145mmol/L [135-145], plasma osmolality 303mOsmol/L [275-295], urine osmolality 483mOsmol/L [300.0-900.0], TSH 1.56mUI/L [0.27-4.20], free T4 0.41ng/dL [0.93-1.70], free T3 1.05pg/mL [2.00-4.40], prolactin 122ng/mL [1.6-27.0], FSH <0.1UI/L [3.5-12.5], LH <0.1UI/L [2.40-12.6], estradiol <10pg/mL [12.5-166], IGF-1 72ng/mL [101-267], calcium 9.8mg/dL [8.1-10.2], ACE 80UI/L [8-52], ESR 101 mm in the 1(st) hour [<21], confirming the presence of central hypothyroidism, hypogonadotrophic hypogonadism, hyperprolactinemia and partial central diabetes insipidus. Adrenal axis was not tested because the patient was treated with dexamethasone for the visual symptoms since the admission. Sarcoidosis diagnosis was confirmed with a pulmonary biopsy. The patient was started on levothyroxine, desmopressin and cabergoline (the last one prescribed intermittently according to the galactorrhea complaints) with clinical and biochemical improvement. Estroprogestative therapy is still under consideration. Dexamethasone was switched to high dose prednisolone for sarcoidosis treatment, being progressively reduced with the introduction of azathioprine. After 3 years of follow-up, the patient is now clinically stable with radiological improvement of the mass with no signs of direct hypothalamic or pituitary lesion, but persistent hypopituitarism and diabetes insipidus. Conclusion: neurosarcoidosis with hypothalamic-pituitary involvement is rare and requires close, prolonged follow-up of the patients because endocrine deficits may persist chronically, even when adequate immunosuppressive treatment of the disease is instituted and apparent radiological improvement occurs.