SUN-049 - Central Diabetes Insipidus and Life-Threatening Panhypopituitarism: Uncovering Neurosarcoidosis in A Young Adult

Diabetes insipidus (DI) is a rare but serious cause of severe hypernatremia and can sometimes be the first sign of infiltrative or inflammatory disorders involving the hypothalamic-pituitary axis. Prompt recognition is vital, as central DI can frequently coexist with anterior pituitary hormone deficiencies that can be life-threatening if unrecognized. Isolated neurosarcoidosis involving the hypothalamic-pituitary axis is exceedingly rare. We present a unique case of a young woman who initially presented with severe hypernatremia and was ultimately found to have central DI in the setting of panhypopituitarism secondary to neurosarcoidosis.

A 34-year-old woman with limited medical history and poor recall presented to the hospital with acute confusion, polyuria, and polydipsia. She reported prior evaluation for seizures but was unable to provide details. Initial labs revealed severe hypernatremia (serum sodium 163mmol/L [135-145 mmol/L]), raising immediate concern for DI. Early management focused on cautious correction of hypernatremia. Anterior pituitary hormones were assessed and revealed panhypopituitarism with secondary adrenal insufficiency (8 AM cortisol 2 µg/dL [4.3-22.4 µg/dL]), central hypothyroidism (free T4 0.60 ng/dL [0.61-1.44 ng/dL]), hypogonadotropic hypogonadism (estradiol 23 pg/mL [23-495 pg/mL], FSH < 1.2 mIU/mL [1.8-22.5 mIU/mL], LH < 0.3 mIU/m [1.2-103 mIU/mL]), and mildly elevated prolactin (25.2 ng/mL [ < 25ng/mL]). The patient was started on desmopressin, which quickly improved her polyuria and normalized her sodium. Hydrocortisone and levothyroxine were initiated to address the adrenal and thyroid deficiencies. Following improvement of her mentation, she reported one year of amenorrhea. Magnetic resonance imaging demonstrated an abnormally thickened, enhancing pituitary stalk with a normal-appearing pituitary gland, as well as leptomeningeal enhancement, raising concern for an inflammatory or granulomatous process. Computed tomography imaging did not reveal evidence of systemic sarcoidosis. Serum angiotensin-converting enzyme levels were normal. Subsequent brain biopsy was thus performed which demonstrated noncaseating granulomas, consistent with neurosarcoidosis.

This case illustrates that central DI may be a clinical manifestation of neurosarcoidosis and may coexist with life-threatening panhypopituitarism. Early and comprehensive evaluation of anterior pituitary function is essential, as prompt identification of anterior pituitary deficiencies not only guides appropriate hormone replacement therapy, but also allows for earlier neuroimaging and diagnosis of infiltrative or inflammatory etiologies. Given the diagnostic challenges of neurosarcoidosis, tissue biopsy remains imperative for definitive confirmation, ultimately enabling timely and targeted management to improve patient outcomes.

*Unless otherwise noted, all abstracts presented at ENDO must not be released to the press or the public until the date and time of presentation. For oral presentations, the abstracts are embargoed until the session begins. The Endocrine Society reserves the right to lift the embargo on specific abstracts that are selected for promotion prior to or during ENDO.*