Adrenal Disorders Flashcards
What hormones are produced in the zona glomerulosa of the adrenal cortex and what is their function?
Mineralocorticoids (aldosterone); regulates salt balance and blood volume
What regulates the secretion of mineralocorticoids (aldosterone)?
Angiotensin II, serum K concentration
What hormones are produced in the zona fasciculata of the adrenal cortex and what is their function?
Glucocorticoids (cortisol); increases blood glucose, metabolic effects
What regulates the secretion of glucocorticoids (cortisol)?
ACTH, corticotropin-releasing hormone
What hormones are produced in the zona reticularis of the adrenal cortex and what is their function?
Androgens (DHEA); converted into testosterone, DHT and estradiol
What regulates the secretion of androgens (DHEA)?
ACTH, corticotropin-releasing hormone
What are the components of the hypothalamic-pituitary-adrenal cortex axis? (6 steps)
Hypothalamus → [CRH] → anterior pituitary → [ACTH] → adrenal cortex → [cortisol]
How does cortisol affect the anterior pituitary and hypothalamus?
Negative feedback
What 2 things does cortisol increase? (part of cortisol functions)
Stimulates gluconeogenesis (↑ blood glucose levels) and ↑ proteolysis in muscle
What 3 things does cortisol decrease? (part of cortisol functions)
↓ glucose uptake by tissues ↓ bone formation ↓ intestinal/ renal calcium absorption → ↓ plasma calcium
How does cortisol play a role in inflammation?
Anti-inflammatory effects
How does cortisol play a role in BP?
Maintains normal BP
Does cortisol inhibit or stimulate collagen formation?
Inhibits
When do levels of cortisol rise/peak/ fall? (circadian rhythm of cortisol)
Levels rise during sleep/ peak in AM & drop throughout the day
Pt presents with moon face and buffalo hump. What are you concerned for?
Cushing’s syndrome
Cushing’s is characterized as excess levels of what?
Glucocorticoid (cortisol) and androgens
Pt presents with amenorrhea, striae, hyperpigmentation, central obesity, osteoporosis, poor wound healing, HTN, depression, anxiety, and excess adrenal androgens causing hirsutism, acne, and increased libido. What condition do they have?
Cushing’s
Does ACTH dependent Cushing’s have high or low cortisol?
High (makes up about 80% of cases)
Does ACTH independent Cushing’s have high or low cortisol?
High (but low ACTH)
What is the primary etiology of ACTH dependent Cushing’s?
Cushing’s disease (pituitary hypersecretion)
Besides Cushing’s disease, what is the other most common etiology of ACTH dependent Cushing’s?
Ectopic secretion by non-pituitary tumor
What is the most common etiology of ACTH indepdent Cushing’s?
Latrogenic or factitious Cushing’s syndrome (administration of excessive synthetic glucocorticoid)
Would an adrenocortical adenoma/ carcinoma and pheochromocytoma cause ACTH dependent or ACTH independent Cushing’s?
ACTH independent
What is the gold standard for diagnosis of Cushing’s?
24 hour urinary free cortisol excretion
Exclusion of exogenous glucocorticoids, late night salivary cortisol, and low-dose dexamethasone suppression test are other diagnostic tests for what condition?
Cushing’s
What is an abnormal result for a low-dose dexamethasone suppression test?
Elevated cortisol of > 5 mcg/dL (suspicious for non-suppressible cortisol production from ACTH independent etiology)
When might you consider imaging (MRI, CXR, pelvic US, CT abdomen) in the diagnosis/ management of Cushing’s?
To rule out other causes
What is the treatment for Cushing’s caused by exogenous corticosteroids?
Taper to lowest therapeutic dose to control sxs
What is the treatment of Cushing’s caused by a pituitary adenoma?
Transsphenoidal resection
What is the treatment of Cushing’s caused by an adrenal tumor?
Adrenalectomy
What is the treatment of Cushing’s caused by adrenal hyperplasia, an inoperable tumor, or other malignancy?
Medical therapy
What is considered 1st line treatment for Cushing’s?
Ketoconazole
If Ketoconazole is ineffective in the treatment of Cushing’s, what might you add to the treatment regimen?
Metyrapone
What might you add to the treatment regimen of a pt with Cushing’s to achieve “medical adrenalectomy”?
Mitotane
What are the primary functions of aldosterone?
Increase BP and promote excretion of potassium (reabsorption of sodium)
What syndrome is excess aldosterone?
Conn’s
What is the most common etiology of Conn’s syndrome?
Bilateral idiopathic adrenal hyperplasia (60%)
What is the second most common etiology of Conn’s syndrome?
Unilateral aldosterone producing adenoma (APA) (30%)
What are the primary sxs of Conn’s syndrome?
Hypertension and hypokalemia (others: muscle weakness, paresthesias, HA, polyuria, polydipsia)
What 3 lab findings are diagnostic for Conn’s?
- Increased plasma aldosterone 2. Decreased plasma renin activity/ concentration 3. Spontaneous hypokalemia
What is first line imaging for Conn’s used to evaluate for adrenal adenoma and adrenal hyperplasia?
CT abdomen
If a pt presents with resistant HTN, what should you evaluate for?
Excess aldosterone
What is the treatment of choice for Conn’s if the cause is a unilateral adrenal adenoma?
Surgical removal
What is 1st line treatment for Conn’s if the cause if bilateral idiopathic adrenal hyperplasia?
Spironolactone (must monitor serum K, creatinine, and BP during first 4-6 weeks of therapy)
Are cortisol levels high/ N/ or low for the following? Primary AI (Addison’s disease) Secondary AI Tertiary AI
All low
Are aldosterone levels high/ N/ or low for the following? Primary AI (Addison’s disease) Secondary AI Tertiary AI
Low, N, N
Are androgen levels high/ N/ or low for the following? Primary AI (Addison’s disease) Secondary AI Tertiary AI
All low
Are ACTH levels high/ N/ or low for the following? Primary AI (Addison’s disease) Secondary AI Tertiary AI
High, low, low
Are CRH levels high/ N/ or low for the following? Primary AI (Addison’s disease) Secondary AI Tertiary AI
High, high, low
What is primary adrenocortical insufficiency and synthesis of which adrenocortical hormones are decreased?
Addison’s, ALL are decreased
Hypoglycemia, weight loss, and muscle weakness are indicative of decreased levels of what?
Cortisol (Addison’s)
Decreased aldosterone causes what 2 sxs besides hyperkalemia and metabolic acidosis?
Hypotension and salt craving (Addison’s)
Decreased libido and pubic hair in females is indicative of decreased levels of what?
Androgens (Addison’s)
What primary sx will be caused by increased ACTH?
Hyperpigmentation (Addison’s)
What is the most common etiology of Addison’s?
Autoimmune destruction of adrenal cortex
S/p adrenalectomy, infection (TB, histo, cocci, HIV), hemorrhage/ infarction, CA/ mets can all be the cause of what condition?
Addison’s
What are the primary sxs of Addison’s? (3)
Hyperpigmentation, salt craving, postural hypotension (also: muscle/joint pain, weight loss, hypoglycemia, depression, confusion, anxiety)
What is the most common etiology of secondary AI?
Suppression of HPA axis by abrupt cessation of exogenous steroid
Pituitary disease, endogenous steroid-producing tumor, and drugs that produce corticosteroids are all possible etiologies for what conditions?
Secondary/ tertiary AI
What are the clinical features of secondary and tertiary AI related to?
Cortisol and androgen deficiency
What are the 2 main differences between primary AI and secondary/ tertiary AI?
Aldosterone is normal and there is NO hyperpigmentation
Failure of corticotrophs to adequately secrete ACTH is what type of AI?
Secondary
Insufficient CRH from the hypothalamus is what type of AI?
Tertiary
What are the 2 best diagnostic methods for AI?
Serum AM cortisol (low) and Cosyntropin (ACTH) stimulation test (can also use serum ACTH, renin, aldosterone)
What test evaluates for the ability of the adrenal gland to respond to ACTH and what should happen?
Cosyntropin (ACTH) stimulation test, should produce cortisol
What is considered an abnormal result for a Cosyntropin (ACTH) stimulation test?
Cortisol fails to increase by 7mg/dL above baseline OR to > 18 mcg/dL
If on Cosyntropin (ACTH) stimulation test you note an exaggerated and prolonged ACTH response, should you be concerned for secondary or tertiary AI?
Tertiary
If on Cosyntropin (ACTH) stimulation test you note an absent or subnormal ACTH response, should you be concerned for secondary or tertiary AI?
Secondary
What is the management for AI? (4)
Short-acting glucocorticoids, long-acting glucocorticoids (if non-compliant w/ short-acting), Mineralocorticoid, oral DHEA replacement (women)
What short-acting glucocorticoids are used in the treatment of AI?
Hydrocortisone BID to TID
What long-acting glucocorticoids are used in the treatment of AI? (if non-compliant w/ short-acting)
Dexamethasone, prednisone
What mineralocorticoid is used in the treatment of AI?
Fludrocortisone
What is defined as a catecholamine-secreting tumor that arises from chromaffin cells of adrenal medulla?
Pheochromocytoma (rare)
Do you see excess or low catecholamines with a pheochromocytoma?
Excess
MEN2 syndrome can be a possible familial cause of what?
Pheochromocytoma (40%)
Are pheochromocytomas more commonly benign or malignant?
90% benign
Paraanglioma can be the cause of what?
Pheochromocytoma
What is the classic triad of sxs associated with a pheochromocytoma?
Episodic HA, tachycardia, sweating (associated w/ paroxysmal HTN)
what instances should you suspect a possible pheochromocytoma? (3)
Paroxysmal “attacks”, refractory HTN (or onset < 20 yo), family history (also: abd/ adrenal mass, other diagnoses (MEN2, NF))
What 3 labs are included in the initial workup for a possible pheochromocytoma?
Plasma metanephrines, 24-hour urine (catecholamines, metanephrines, VMA), Clonidine Suppression Test (can also order plasma epi/ NE)
What imaging would you order after a lab dx of pheochromocytoma has been made?
CT abdomen w/o contrast
What is the 1st line management for pheochromocytoma?
“Chemical sympathectomy” to stabilize until surgery (which is definitive)
What pharmacologic treatment might be used for the management of a pheochromocytoma?
Pure alpha-blocker (phenoxybenzamine) and beta-blocker (propranolol)
An adrenal mass lesion > 1 cm in diameter and serendipitously discovered by imaging but RARE is what?
Adrenal incidentaloma
What is included in the workup of ALL pts with possible adrenal incidentaloma?
R/o pheochromocytoma and subclinical Cushing’s Syndrome
What is included in the workup of pts with HTN at presentation with possible adrenal incidentaloma?
R/o primary aldosteronism
What is included in the workup of pts with a hx of a primary malignanct elsewhere with possible adrenal incidentaloma?
DO NOT biopsy if biochemical evidence of pheo or if known widespread metastatic disease
What is the management for possible adrenal incidentaloma if workup is negative + likely benign + < 2cm? (2)
Repeat imaging @ 6 months, repeat dexamethasone suppression test annually x 4 years
What is the management for possible adrenal incidentaloma if workup is negative + likely benign + > 2cm?
Consider surgical resection
What is dexamethasone?
Potent glucocorticoid
What disease does the following correspond to?
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Cushing’s syndrome
What disease does the following test/ abnormal results correspond to?
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Addison’s disease
What disease does the following test/ abnormal results correspond to?
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Pheochromocytoma