Case report: Primary empty Sella causing secondary adrenal insufficiency and severe yet asymptomatic hyponatremia

A 61‐year‐old man presented with incidental hyponatraemia to 118 mmol/L, to which he was asymptomatic. Diagnostic workup revealed a partially empty sella turcica on magnetic resonance imaging. He had associated secondary adrenal insufficiency but other hormonal axes were relatively unaffected. Treatment with cortisol replacement promptly resolved the hyponatraemia.