Pituitary microadenoma with hypopituitarism presenting as hyponatremia

The incidence of pituitary adenoma has been increasing these days. Majority of the cases are incidental findings on imaging; and these patients may be asymptomatic without any laboratory abnormalities. However, a non-functional sellar mass can initially present with hypopituitarism. The patient being described is an elderly female who presented with severe hyponatraemia. She has history of recurrent admissions for hyponatraemia in the past. Her biochemical evaluation revealed hypopituitarism and magnetic resonance imaging of brain showed pituitary microadenoma. Hyponatraemia as a presenting feature of hypopituitarism due to pituitary microadenoma is an uncommon scenario.