Cushing`s syndrome

What is it

This disorder is characterised by an excess of glucocorticoids or steroid production in the body.

Who it affects

Cushing`s syndrome is a rare disorder affecting 1 per 500,000 people.

What gland is involved

Cushing`s syndrome may result from excessive ACTH release from the pituitary gland (Cushing`s disease) or excess cortisol production by the adrenal gland. It may also arise from steroid use in other medical conditions and rarely by unusual sources of ACTH production.

Symptoms

Patients may experience symptoms such as facial fullness, weight gain, changes in fat and muscle distribution, lilac coloured stretch marks, excess fat tissue around the upper back, diabetes and osteoporosis.

Diagnosis

Initial investigations that may be performed in Cushing`s syndrome include a series of blood tests and 24hr urine collections. Some of the tests performed will involve the administration of steroid tablets and blood tests carried out over a number of days (see low dose Dexamethasone suppression test). Hospital admission during this time is sometimes required.

Once, a diagnosis of Cushing`s syndrome is confirmed doctors will investigate further to clarify the cause of the excess steroids. These investigations may include further blood tests (see high dose Dexamethasone suppression test), CT or MRI scans of the relevant parts of the body.

Treatment

This depends on the cause of Cushing`s syndrome. Pituitary and adrenal causes are usually due to discrete benign tumours that are over-secreting hormones and these are usually amenable to surgery. Pituitary radiotherapy may also play a role in the management of patient with Cushing`s disease.

Frequently, medication such as Ketoconazole and or Metyrapone will be used to control Cushing`s syndrome prior to surgery. This not only improves a patient`s symptoms, but also helps to improve tissue healing that is so important in surgery.

Outlook

The majority of patients notice a significant improvement in quality of life with treatment. The longer-term outlook in a patient with Cushing`s disease is dependent on the underlying cause, duration of the disease and how well cortisol levels are controlled using the above treatments.