Twist of endocrine scenario: Approach of ectopic Cushing syndrome (review)

Abstract

Ectopic Cushing syndrome or ectopic ACTH (Adrenocorticotropic Hormone) syndrome, a rare but severe condition, is due to a non-pituitary ACTH excess or exceptionally a non-hypothalamic CRH (Corticotropin - Releasing Hormone) hyper-production, usually due to a neoplasia which may be of endocrine or nonendocrine origin. Our objective is to introduce a brief literature regarding ectopic Cushing syndrome based on five micro-chapters: clinical evaluation, lab tests, imaging assays, therapy options and as discussions – the current limits of the topic. This actually comes with a twist in every aspect since a lot of data are yet to be clarify about this complex medical entity. Clinical presentation may be suggestive for Cushing syndrome but a few characteristics are more frequently seen as hyperpigmentation, rapid onset up even becoming an endocrine emergency, male preponderance, potential weight loss instead of weight gain, as oppose to Cushing disease or adrenal Cushing syndrome. Hypokalaemia is a hallmark of this particular situation. Additional tests are necessary to identify the source of ACTH excess and this twist is necessary in addition to traditional suppression tests for glucocorticoid axes. Some authors describe another twist in recognition of syndrome presentation: that actually there are two subtypes – one caused by a very aggressive tumour with rapid evolution and another with a lent slope of clinical features appearance caused by a occult neoplasm. Another twist is the fact that, in cases without a clear tumour origin, bilateral adrenal removal is actually necessary until adequate identification of source is done (if ever). Overall, a complex multidisciplinary team is necessary, the prompt recognition and therapy is life saving and numerous limits of both diagnosis and management are still a matter of debate.

Keywords

• cushing’s syndrome
• cancer
• adrenalectomy
• adrenal tumour
• cortisol