Cushing's Syndrome

Cushing’s Syndrome is a rare disease characterised by persistent high levels of cortisol, a hormone that triggers anti-inflammatory actions in response to stressful situations such as illness or injury.

Excessive secretion of cortisol can lead to chronic disorders, such as hypertension and glucose intolerance. Other Cushing’s Syndrome symptoms include easy bruising, facial plethora, depression, decreased libido and osteopenia. If left untreated, Cushing’s Syndrome can become life-threatening as a result of malignancy, overwhelming infection and organ failure.

High levels of cortisol may be due to endogenous triggers such as endocrine tumours (pituitary, adrenal or ectopic tumours), or exogenous sources such as high doses of corticosteroid treatment. Cortisol release may be further influenced by high levels of adrenocorticotropic hormone (ACTH), a factor that regulates cortisol release from the adrenal glands. Diagnosis of Cushings’ syndrome is therefore based on progressive signs and symptoms and multiple tests including the urinary free-cortisol test, salivary cortisol test and the low-dose dexamethasone suppression test (LDDST).

If possible and appropriate, first-line treatment is surgical resection of any primary tumours (pituitary adenoma, non-pituitary tumour secreting ACTH, or adrenal tumours). Second-line therapies include repeat transsphenoidal surgery (TSS), radiation therapy/radiosurgery, bilateral adrenalectomy and treatments such as neuromodulators of ACTH release, adrenal steroidogenesis inhibitors and glucocorticoid receptor blockers.