Forty Years Of Unrecognized Hypopituitarism Diagnosed By Physical Exam

Abstract Objective: To describe the diagnosis of a case of hypopituitarism that went undiagnosed for 40 years, having been masked by inhaled glucocorticoids. Methods: We present the clinical, laboratory, exam, and imaging findings, along with a review of the literature. Results: A 58-year-old man with a history of intermittent hyponatremia of unknown etiology and chronic abdominal cramps presented with worsening cramps, confusion, and serum sodium of 112 mmol/L (reference range, 135 to 145 mmol/L). His urine sodium and osmolality suggested the syndrome of inappropriate antidiuretic hormone (SIADH), but serum sodium did not normalize with hypertonic saline and fluid restriction. Exam revealed no axillary or pubic hair and no palpable testes. He reported 3 episodes of traumatic head injury around the age of 18 and an inability to have an erection since that time. Further testing found undetectable luteinizing hormone, undetectable testosterone, low free thyroxine, low insulin-like growth factor 1, and a failed cosyntropin stimulation test. Magnetic resonance imaging showed an empty sella. His sodium and cramping improved rapidly with hydrocortisone. He had not used his glucocorticoid inhaler for 3 days prior to admission. He had a similar admission after stopping his inhaler 4 years ago, leading us to the conclusion that the chronic inhaled glucocorticoid may have masked his hypopituitarism. Conclusion: This case highlights the common and life-threatening delay in diagnosis of adrenal insufficiency, the need to consider SIADH a diagnosis of exclusion, and the importance of a thorough physical exam and history, even in this era of digital medicine. Abbreviations: Siadh syndrome of inappropriate antidiuretic hormone T4 thyroxine