A case of hypocalcaemia in ectopic ACTH production

Clinical presentation A 70 year old female presented with general lethargy and a two day history of painful muscle twitching and paraesthesia in her right hand. Past medical history included hypertension, hypothyroidism and she had recently been diagnosed with type 2 diabetes. Examination was unremarkable. The overall biochemical picture was that of a hypokalaemic alkalosis with hypocalcaemia and hyperglycaemia. Venous gas showed a metabolic alkalosis (pH 7.51, HCO 3 32.4). CXR revealed a mass at the superior aspect of the right hilum.