Cushing's disease

Question 1

Definition

Answer 1

A disorder that occurs when your body makes too much of the hormone cortisol over a long period of time

Question 2

Aetiology

Answer 2

Most cases occur from the administration of synthetic steroids or ACTH (adrenocorticotrophic hormone) for the treatment of certain medical conditions e.g: asthma

MC cause:
– therapeutic administration of synthetic steroids (iatrogenic)

Spontaneous cushings syndrome is rare
– pituitary tumours account for 65% of spontaneous cushings syndrome

ACTH-dependant cases:
– pituitary dependant (pituitary adenoma, cushings disease)
– ectopic ACTH-producing tumours (small-cell lung cancer, carcinoid tumours)
– ACTH administration

Non-ACTH dependant cases:
– adrenal carcinomas
– adrenal adenomas
– glucocorticoid administration

Others:
– alcohol induced pseudo-Cushing’s syndrome

Must be differentiated from cushings syndrome :
— cushings syndrome- term which refers to the abnormalities resulting from a chronic excess of glucocorticoids whatever the cause, where Cushing’s disease specifically refers to excess glucocorticoids resulting from inappropriate ACTH secretion from the pituitary

Question 3

Clinical presentation

Answer 3

Pt’s are obese:
– fat distribution is typically central, affecting the trunk, abdomen and neck (buffalo hump)

– plethoric complexion with a moon face (causes redness in light complexions and brown discolouration in darker skin tones)
– skin is thin, bruises easily and there are purple striae on the abdomen, breasts and thighs
– slow healing of cuts
– acne
– depression
– psychosis

Other features:
– proximal myopathy (symmetrical weakness of proximal upper and/or lower limb)
– hypertension
– hypokalaemia
– impaired glucose tolerance

Signs and symptoms women may experience:
– thicker or more visible body and facial hair
– irregular or absent menstrual periods

Signs and symptoms men may experience:
– decreased sex drive
– decreased fertility
– erectile dysfunction

MC symptoms and signs to differentiate from normal obesity:
– mental changes
– general plethora
– moon face
– hypertension
– thin skin that bruises easily
– musculoskeletal problems like osteoporosis
– proximal myopathy