A chronic smoker presented with mild haemoptysis. He also gave a history of hypeension and obesity. Lab data showed raised ACTH levels, which were not suppressed by high dose dexamethasone. The cause for the Cushing's syndrome in the patient is :
High-Yield Explanation
Answer is D (Ectopic ACTH secreting tumor) : Raised ACTH levels not suppressible by high dose dexamethosone in the backdrop of chronic smoking and hemoptysis lead us to a diagnosis of ectopic ACTH secretion from a bronchogenic carcinoma.