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Factsheet 5 Cushing’s disease (i.e. an ACTH-secreting pituitary adenoma) is the most common cause of spontaneous Cushing’s syndrome; other causes are an adrenal tumour or an ectopic tumour secreting ACTH. Spontaneous Cushing’s syndrome is caused by excessive circulating Cortisol; it is rare but is associated with a significant increase in morbidity and mortality, even if treated. Cushing’s syndrome may also be the
unavoidable result of steroid treatment for allergy, asthma, arthritis or other life-threatening condition. Diagnosis and differential diagnosis of Cushing’s syndrome is complex and referral to a specialist centre is recommended in all cases in whom the condition is suspected. The recommended route of referral is through an Endocrinologist rather than neurosurgeon or others. Please see ‘Who and When to Refer’ (factsheet 15). 
PRESENTING SYMPTOMS moon face - particularly filling in of the temporal fossa weight gain - central obesity muscle wasting and proximal myopathy (patients have difficulty standing from a seated position without use of arms) thin skin - tendency to bruise hirsutism (caused by androgen excess) violaceous stria hypertension diabetes psychiatric disturbance (often characterised by amplification of previous personality traits)
INVESTIGATIONS
Overnight dexamethasone suppression test and/or 24 hour urinary cortisol measurements. If this indicates Cushing’s syndrome further tests to confirm the diagnosis and to determine the source of excessive cortisol will be required. Normal screening tests do not always exclude the diagnosis - if clinical suspicion is high then specialist referral may still be necessary. During diagnosis and differential diagnosis further dynamic endocrine tests, chest X-ray and pituitary, adrenal and lung/abdomen MRI or CT scans may be required. TREATMENT POSSIBILITIES
Transsphenoidal surgery is usually the recommended treatment if the condition is due to a Pituitary tumour. In cases where surgery is contra-indicated or fails to reduce cortisol levels, Adrenalectomy and/or pituitary Radiotherapy may be necessary. PATIENT MANAGEMENT
POST-OPERATIVE
Patients in remission normally undergo substantial changes immediately after surgery which, apart from welcome changes in physical appearance and resolution of other symptoms and signs, may initially involve depression. This is the result of the profound change in steroid status. No further treatment may be required except monitoring for recurrence of Cushing’s and regrowth of the tumour. However, most patients will require Hydrocortisone therapy, some on a long-term basis. If the patient needs hydrocortisone for more than one year postoperatively, the outlook for long-term remission is excellent. If surgery results in hypopituitarism, long-term hormone replacement therapy will be required (factsheet 12). LONG-TERM
Patients require close follow up on a long-term basis. Pituitary hormone replacement therapy will be required after surgery in some cases, and requires careful specialist monitoring. Advice should be given regarding the dose of steroid to be taken during intercurrent illness (factsheet 12). Long-term effects of radiotherapy may also include the development of partial or complete hypopituitarism. Patients may need help to follow a suitable diet and encouragement to take regular exercise to control weight gain. WATCHPOINTS
Urgent - refer to hospital Non-urgent (but still very important) If the patient is on hydrocortisone, ensure that replacement therapy is increased when seriously ill or under major physical or psychological stress Patients may have major mood swings after successful treatment to lower circulating corticosteroids. This can last for many months, so reassurance and treatment for depression may be necessary Obesity is often the aspect of Cushing’s disease that female patients find most distressing. Weight reduction following successful treatment is often slow Patients will need exercises to restore muscle strength and possibly further treatment for osteoporosis
QUESTIONS PATIENTS MAY ASK Why am I putting on weight?
Increased cortisol causes accumulation of fat deposits and a redistribution of fats to the face, neck and abdomen. Why am I getting hairy?
ACTH stimulates increased secretion of Androgens from the adrenal cortex causing hirsutism. Why do I feel so weak?
Hypersecretion of cortisol causes the increased breakdown of tissue proteins. One effect of this is muscle wasting, which mainly affects the muscles of the upper arms and thighs. This can make it difficult to climb stairs, or stand after sitting. Why am I so moody?
The excess steroid produced by the tumour has a direct effect on the brain. It tends to produce dramatic mood swings. Why do I bruise so easily?
Increased breakdown of tissue proteins causing weakening of capillaries. Why have I developed stretch marks?
Increased breakdown of skin proteins makes the skin more fragile Why do I have backache?
As above - the back muscles are weakened by the steroids and the extra weight which you gain also puts a strain on them. The steroids also affect the bones of the back. Have I inherited this, will my children get it?
In all but very exceptional circumstances there is no hereditary link.
RESOURCES FOR PATIENTS
available from The Pituitary Foundation HelpLine or our website www.pituitary.org.uk or our Endocrine Nurse HelpLine
Patient Information Booklet: Cushing’s
Other information and resource links available at www.pituitary.org.uk FOR GPs MORE SPECIALIST RESOURCES Management of Pituitary Tumors: The Clinician’s Practical Guide (2003) (Second Edition), Editors and authors Michael P. Powell, Stafford L. Lightman and Edward R. Laws. Humana Press, Totowa, New Jersey Pituitary Tumours. Recommendations for service provision and guidelines for management of patients. Consensus statement of a working party (1997) RN Clayton & JAH Wass (Eds) London: Royal College of Physicians The Epidemiology, Pathogenesis and Management of Pituitary Tumours (1998) Webb SM (Ed)Bristol, UK: BioScientifica Oxford Textbook of Endocrinology OUP (2002) JAH Wass & S Shalet (Eds)
©2011 Version 3 (To be reviewed by 2013)
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