A 68-year-old man with small-cell lung cancer develops hyponatraemia with a serum sodium of 118 mmol/L. He is euvolaemic on examination and has normal...

Question

A 68-year-old man with small-cell lung cancer develops hyponatraemia with a serum sodium of 118 mmol/L. He is euvolaemic on examination and has normal renal, adrenal and thyroid function. What is the most likely underlying mechanism?

Accepted Answer

Syndrome of inappropriate antidiuretic hormone secretion

Answer

Primary polydipsia

Answer

Primary hyperaldosteronism

Answer

Diuretic-induced salt loss

Answer

Adrenal insufficiency

uk-plab-1 MCQ (SBA): Syndrome of inappropriate antidiuretic hormone secretion

A 68-year-old man with small-cell lung cancer develops hyponatraemia with a serum sodium of 118 mmol/L. He is euvolaemic on examination and has normal renal, adrenal and thyroid function. What is the most likely underlying mechanism?