A 59-year-old smoker has proximal myopathy, bruising and new diabetes. Potassium is 2.7 mmol/L and bicarbonate is 35 mmol/L. Overnight dexamethasone

Question

A 59-year-old smoker has proximal myopathy, bruising and new diabetes. Potassium is 2.7 mmol/L and bicarbonate is 35 mmol/L. Overnight dexamethasone does not suppress cortisol, ACTH is high and CT chest shows a central lung mass with mediastinal nodes. What is the most likely cause?

Accepted Answer

Ectopic ACTH production by small cell lung cancer

Answer

Autonomous aldosterone secretion by adrenal adenoma

Answer

Exogenous glucocorticoid withdrawal

Answer

Primary adrenal destruction

Answer

Pituitary prolactinoma

Ectopic ACTH syndrome — RCPSC IM MCQ

A 59-year-old smoker has proximal myopathy, bruising and new diabetes. Potassium is 2.7 mmol/L and bicarbonate is 35 mmol/L. Overnight dexamethasone does not suppress cortisol, ACTH is high and CT chest shows a central lung mass with mediastinal nodes. What is the most likely cause?