Cushing Syndrome Flashcards
General Considerations
Cushing Syndrome
Cushing Disease
Cushing “syndrome”
Commonly due to exogenous corticosteroid drugs
Cushing “disease”
40% due to ACTH hypersecretion by a pituitary adenoma
10% due to ectopic ACTH
15% due to ACTH unknown source (initially)
30% due to excessive autonomous secretion of cortisol
Spontaneous CS rare: 2.6 new cases yearly/million population
ACTH-secreting pituitary adenoma > 3 times more common in women than men
Key Features: Essentials of Dx - Clinical Presentation
Central obesity, moon face Muscle wasting Thin skin, purple striae, hirsutism, poor wound healing Psychological changes Osteoporosis, hypertension
DD
Chronic alcoholism (alcoholic pseudo-Cushing syndrome)
Diabetes mellitus
Polycystic Ovarian Disorder
Depression (may have hypercortisolism)
Osteoporosis due to other causes
Obesity due to other cause
Primary hyperaldosteronism
Anorexia nervosa (high urine-free cortisol)
Striae distensae (“stretch marks”) seen in adolescence & pregnancy
Lipodystrophy from antiretroviral agent
Dx Workup
Dexamethoasone suppression test: 1mg PO dexamethasone given at 2300 and blood drawn at 0800 for cortisol determination
cortisol level <5mcg/dL excludes CS with some certainty
When other s&s for hyperaldosteronism present, question results
Management
Refer or consult endocrinologist Identify cause of problem Remove cause of cortisol excess Iatrogenic Cushing’s syndrome: Terminate therapy Control signs & symptoms if cannot stop therapy Pituitary Cushing’s Syndrome: Removal of pituitary tumor
Prognosis
Manifestations regress with time
Often residual mild cognitive impairment, muscle weakness, osteoporosis
Younger have better chance for recover
Children with short stature may have catch-up growth following cure
Prognosis depends on source of excess cortisol
Essentials of Dx - Labs
Hyperglycemia, leukocytosis, lymphocytopenia, hypokalemia, glycosuria
Elevated serum cortisol & urinary-free cortisol
Lack of normal suppression by dexamethasone
