Signs + symptoms
Cushing’s syndrome Moon face
Buffalo hump
Central obesity
Acne
Definition endocrine disorder w/ HTN
elevated cortisol levels in the blood Hyperglycaemia
Aetiology Exogenous > Endogenous Striae
Vertebral collapse
ACTH-dependent causes Proximal muscle wasting
o Cushing’s disease (80%): Psychosis
Hypokalaemic metabolic alkalosis
pituitary tumour secreting ACTH Impaired glucose tolerance test
producing adrenal hyperplasia
o Ectopic ACTH production (5-
10%) e.g. small cell lung cancer
Ix
ACTH-independent causes Diagnostic tests urinary free
o Iatrogenic: steroids cortisol, low-dose/high-dose
o Adrenal adenoma (5-10%) dexamethasone suppression test
o Adrenal carcinoma (rare) Bloods FBC, U&Es, LFTs, glucose,
o Carney complex: syndrome lipid profile
Radiology CXR (look for lung
including cardiac myxoma
cancer/vertebral collapse/signs of
o Micro-nodular adrenal dysplasia osteoporosis)
Other DEXA
Pseudo-Cushing’s
o Often due to excess Confirming Cushing’s
alcohol/severe depression Overnight Dexamethasone
o Causes false positive suppression test (most sensitive)
24h urinary free cortisol
dexamethasone suppression Localisation tests
test/24h urinary free cortisol The first line localisation test is
o Insulin stress test may be used 9:00am + midnight plasma ACTH
to differentiate (+cortisol) levels
If ACTH is suppressed then a non-
ACTH dependent cause is likely
such as adrenal adenoma
High-dose Dexamethasone
suppression test done if:
Pituitary source cortisol
suppressed
Mx If ectopic/adrenal no change in
Conservative cortisol
o Reduce alcohol CRH stimulation
Medical If pituitary source High cortisol
o Ketoconazole, Metyrapone If ectopic/adrenal no change
o Rx HTN + blood glucose Petrosal sinus sampling of ACTH
differentiate between pituitary +
monitoring
ectopic
Surgical
o Trans-sphenoidal surgery to
remove adenoma/bilateral
adrenalectomy
Cushing’s syndrome Moon face
Buffalo hump
Central obesity
Acne
Definition endocrine disorder w/ HTN
elevated cortisol levels in the blood Hyperglycaemia
Aetiology Exogenous > Endogenous Striae
Vertebral collapse
ACTH-dependent causes Proximal muscle wasting
o Cushing’s disease (80%): Psychosis
Hypokalaemic metabolic alkalosis
pituitary tumour secreting ACTH Impaired glucose tolerance test
producing adrenal hyperplasia
o Ectopic ACTH production (5-
10%) e.g. small cell lung cancer
Ix
ACTH-independent causes Diagnostic tests urinary free
o Iatrogenic: steroids cortisol, low-dose/high-dose
o Adrenal adenoma (5-10%) dexamethasone suppression test
o Adrenal carcinoma (rare) Bloods FBC, U&Es, LFTs, glucose,
o Carney complex: syndrome lipid profile
Radiology CXR (look for lung
including cardiac myxoma
cancer/vertebral collapse/signs of
o Micro-nodular adrenal dysplasia osteoporosis)
Other DEXA
Pseudo-Cushing’s
o Often due to excess Confirming Cushing’s
alcohol/severe depression Overnight Dexamethasone
o Causes false positive suppression test (most sensitive)
24h urinary free cortisol
dexamethasone suppression Localisation tests
test/24h urinary free cortisol The first line localisation test is
o Insulin stress test may be used 9:00am + midnight plasma ACTH
to differentiate (+cortisol) levels
If ACTH is suppressed then a non-
ACTH dependent cause is likely
such as adrenal adenoma
High-dose Dexamethasone
suppression test done if:
Pituitary source cortisol
suppressed
Mx If ectopic/adrenal no change in
Conservative cortisol
o Reduce alcohol CRH stimulation
Medical If pituitary source High cortisol
o Ketoconazole, Metyrapone If ectopic/adrenal no change
o Rx HTN + blood glucose Petrosal sinus sampling of ACTH
differentiate between pituitary +
monitoring
ectopic
Surgical
o Trans-sphenoidal surgery to
remove adenoma/bilateral
adrenalectomy
