A collapse with hypertension and hypokalaemia

A 60 year old white man was admitted from the emergency department after an unwitnessed collapse and generalised weakness and malaise. He had no medical history of note and was taking no drugs. On clinical assessment he had hypertension, which had not previously been documented, with a blood pressure of 187/91 mm Hg. Blood tests showed severe hypokalaemia (2.1 mmol/L (reference range 3.6-5.0), having been normal (4.7) nine months earlier) and metabolic alkalosis (bicarbonate 38 mmol/L, 22-30). Random blood glucose was 6.0 mmol/L (3.5-7.8).

On the post take ward round, he was noted to have clubbing of the nails and a tanned appearance. A 60 pack year smoking history was elicited. Further biochemical tests were requested and, because his chest radiograph was abnormal, chest computed tomography was performed (fig 1⇓).