SAT-LB082 Neurosarcoidosis Presenting as Panhypopituitarism, Diabetes Insipidus and Sellar Mass

Abstract

Introduction: Granulomatous hypophysitis is a rare entity with an annual incidence of 1 in 10 million. It may be primary or secondary to tuberculosis, sarcoidosis, Wegener’s disease, syphilis or mycotic infections. It accounts for <1 % of cases of panhypopituitarism or visual field defects. Isolated Neurosarcoidosis without systemic involvement is extremely rare. It can rarely present as an isolated granuloma of the sella mimicking pituitary adenoma. Case: A 47-year-old-male was admitted with generalized weakness of 1 month and headache with loss of peripheral vision of 1 week duration. MRI brain revealed a sellar mass with suprasellar extension involving the pituitary stalk and hypothalamus representing pituitary macroadenoma. Biochemical tests were evident for central hypoadrenalism, secondary hypothyroidism and hypogonadism with mild hyperprolactinemia. He had low urine specific gravity on admission and provided history of increased thirst, polyuria and nocturia from past 3 weeks. CSF analysis showed elevated CSF protein and ACE levels. Visual field testing revealed bitemporal hemianopsia. Patient underwent transsphenoidal biopsy and partial resection of pituitary mass with significant improvement in visual field defects post operatively. Pituitary biopsy showed non-necrotizing granulomatous hypophysitis. CT chest revealed hilar and mediastinal lymphadenopathy suspicious of sarcoidosis. He had positive Quantiferon and PPD testing but hilar lymph node biopsy was negative for granuloma or malignancy. CSF analysis, pituitary and lymph node biopsy were negative for bacterial, AFB and fungal culture/stain. Tests for HIV, hepatitis, syphilis, lymphoma panel and sputum AFB culture x3 were negative. He was discharged on levothyroxine, hydrocortisone, testosterone and desmopressin. He completed treatment for latent TB and was monitored as outpatient. After 8 months, his visual field defects had completely recovered. Patient was asymptomatic with unchanged hilar and mediastinal lymphadenopathy. Repeat MRI brain showed avidly enhancing thickened pituitary stalk with complete resolution of pituitary mass lesion. He was diagnosed with probable Neurosarcoidosis and referred to rheumatology. Discussion: Hypothalamic-pituitary sarcoidosis occurs in less than 10% of patients with Neurosarcoidosis. Polyuria, polydipsia and signs and symptoms of hyperprolactinemia are the most common presenting manifestations. Earlier, the endocrine dysfunction was attributed to a destructive process affecting pituitary, but pituitary responsiveness to synthetic hypothalamic releasing factors indicates that hypothalamic insufficiency is the major cause for panhypopituitarism. Diabetes Insipidus can be masked by secondary adrenal deficiency on presentation. Clinicians should be cautious of unmasking diabetes insipidus while replacing glucocorticoids in such cases. Unless otherwise noted, all abstracts presented at ENDO are embargoed until the date and time of presentation. For oral presentations, the abstracts are embargoed until the session begins. s presented at a news conference are embargoed until the date and time of the news conference. The Endocrine Society reserves the right to lift the embargo on specific abstracts that are selected for promotion prior to or during ENDO.