Symptomatic Syndrome of Inappropriate Antidiuretic Hormone Secretion in Pituitary Apoplexy: A Case Report and Literature Review

Abstract

ABSTRACT Objective: We present a case and a review of relevant literature demonstrating that pituitary apoplexy rarely presents with syndrome of inappropriate antidiuretic hormone secretion (SIADH)-induced hyponatremia. We discuss management strategies, including consideration of pituitary surgery in the absence of visual disturbance if conservative management fails to control profound hyponatremia. Methods: Case report with literature review. Results: A previously healthy, 32-year-old female with a history of regular menses presented with fatigue, lethargy, severe headache, and intractable nausea with emesis. At presentation she was clinically euvolemic with intact visual fields and had hypoosmolar hyponatremia with serum sodium 109 mmol/L, serum osmolality 232 mOsm/kg, urine sodium 114 mmol/L, and urine osmolality 374 mOsm/kg. Her thyroid-stimulating hormone concentration was low normal, with a free thyroxine concentration of 0.6 ng/dL and a random serum cortisol measurement of 8.7μmg/dL. Pituitary magn...