An uncommon case of Cushing’s syndrome : ectopic ACTH secretion

Abstract

Cushing’s syndrome (CS) is the end result of long-standing exposure to increased levels of cortisol. This can be divided into two groups: exogenous and endogenous hypercortisolaemia. The former is usually the result of prolonged exposure to synthetic glucocorticoids. On the other hand, endogenous causes result from increased release of cortisol by the adrenal glands and can be ACTH-dependent or ACTH-independent. 80% of endogenous CS is due to ACTH-dependent cortisol excess secondary to a pituitary adenoma [1]. The remaining endogenous causes of CS are due to ACTH-independent adrenal causes (adrenal hyperplasia, adrenal adenomas, and adrenal carcinomas), followed by unknown sources, and ectopic ACTH secretion by neoplasms. The authors present a case of ectopic ACTH-dependent hypercortisolism due to an aggressive metastatic neuroendocrine tumour.