The differential diagnosis of Cushing's syndrome requires careful multidisciplinary interaction with a number of specialities, co-ordinated through endocrine centres with good experience of this condition. It is essential that the diagnosis of Cushing's syndrome be fully established before differential diagnosis is attempted. The endocrinologist needs to be aware of the pitfalls and advantages of the tests in use. We discuss the approach to the differential diagnosis of this challenging condition.
Cushing's syndrome; Cortisol; ACTH; Dexamethasone; Adrenal; Pituitary