Ectopic adrenocorticotropic secretion (EAS) is responsible for 12-17% of cases of Cushing’s syndrome (CS) and covers a range of tumours, from undetectable benign lesions to widespread metastases. The syndrome is often associated with severe hypercortisolaemia, which aggravates the underlying condition. EAS requires a complete workup that includes the establishment of endogenous CS, diagnosis of adrenocorticotropic hormone (ACTH) dependency, localization of the source of ACTH secretion and rapid biochemical control of hypercortisolaemia. Dynamic endocrine tests should include inferior petrosal sinus sampling […]