Management of the Patient with Suspected Cushing's Syndrome

Management of the Patient with Suspected Cushing's Syndrome - Flowchart

«Flowchart»

ALGORITHM FOR MANAGEMENT OF THE PATIENT WITH SUSPECTED CUSHING’S SYNDROME

ALGORITHM FOR MANAGEMENT OF THE PATIENT WITH SUSPECTED CUSHING’S SYNDROME LGORITHM FOR ANAGEMENT OF THE ATIENT WITH USPECTED USHING’S YNDROME

End

Clinical suspicion of Cushing’s
(Central adiposity, proximal myopathy, striae, amenorrhea, hirsutism, impaired glucose tolerance, diastolic hypertension, and osteoporosis)

Clinical suspicion of Cushing’s

Screening/confirmation of diagnosis

24-h urinary free corrtisol excretion increased above normal (3x)
Dexamethasone overnight test (Plasma cortisol >50 nmol/L at 8–9 AM after 1 mg dexamethasone at 11 PM)
Midnight plasma cortisol >130 nmol/L (or midnight salivary cortisol >5 nmol/L)

If further confirmation needed/desired:

Low dose DEX test (Plasma cortisol >50 nmol/L after 0.5 mg dexamethasone q6h for 2 days)

Screening/confirmation of diagnosis

If further confirmation needed/desired:

Low dose DEX test (Plasma cortisol >50 nmol/L after 0.5 mg dexamethasone q6h for 2 days)

Screening/confirmation of diagnosis

If further confirmation needed/desired:

If further confirmation needed/desired: If further confirmation needed/desired:

Low dose DEX test (Plasma cortisol >50 nmol/L after 0.5 mg dexamethasone q6h for 2 days)

Positive

Negative

ACTH-independent Cushing’s

ACTH-dependent Cushing’s

Differential diagnosis 1: Plasma ACTH

Differential diagnosis 1:

ACTH normal or high >15 pg/ml

ACTH suppressed to <5 pg/ml

Cushing’s disease

Differential diagnosis 2

MRI pituitary
CRH test (ACTH increase >40% at 15–30 min + cortisol increase >20% at 45–60 min after CRH 100 µg IV)
High dose DEX test (Cortisol suppression >50% after q6h 2 mg DEX for 2 days)

Differential diagnosis 2

MRI pituitary
CRH test (ACTH increase >40% at 15–30 min + cortisol increase >20% at 45–60 min after CRH 100 µg IV)
High dose DEX test (Cortisol suppression >50% after q6h 2 mg DEX for 2 days)

Differential diagnosis 2

MRI pituitary
CRH test (ACTH increase >40% at 15–30 min + cortisol increase >20% at 45–60 min after CRH 100 µg IV)
High dose DEX test (Cortisol suppression >50% after q6h 2 mg DEX for 2 days)

CRH test and high dose DEX positive

Equivocal results

CRH test and high dose DEX negative

Ectopic ACTH production

Trans-sphenoidal pituitary surgery

Locate and remove ectopic ACTH source

Inferior petrosal sinus sampling (petrosal/peripheral ACTH ratio >2 at baseline, >3 at 2–5 min after CRH 100 µg i.v.)

Pos.

Neg.

Bilateral adrenalectomy

Adrenal tumor workup

Unenhanced CT adrenals

Bilateral micronodular or macronodular adrenal hyperplasia

Unilateral adrenal mass

Unilateral adrenalectomy