Chapter 21: Adrenal Flashcards Preview

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Flashcards in Chapter 21: Adrenal Deck (112):
1

vascular supply: superior adrenal

inferior phrenic artery

2

vascular supply: middle adrenal

aorta

3

vascular supply: inferior adrenal

renal artery

4

drainage of left adrenal vein

left renal vein

5

drainage of right adrenal vein

inferior vena cava

6

Innervation of medulla

sympathetic splanchnic nerve

7

innervation of adrenal cortex

no innervation of adrenal cortex

8

lymphatic drainage of adrenal

lymphatics drain to subdiaphragmatic and renal lymph nodes

9

what makes up the adrenals

made up of adrenal cortex and adrenal medulla

10

incidence of incidentaloma of adrenal mass on CT scan

1%-2% of abdominal CT scans show incidentaloma (5% are metastases)

11

two things to know about asymptomatic adrenal masses

- benign adenomas are common
- adrenals are also common site for metastases

12

what to do when you see an asymptomatic adrenal mass?

check for functioning tumor: urine metanephrines/vma/catecholamines, urinary hydroxycorticosteroids, serum K with plasma renin and aldosterone levels
- Consider CXR, colonoscopy, mammogram to check for a primary tumor

13

when is surgery indicated for asymptomatic adrenal mass?

ominous characteristics (non-homogenous), is > 4-6 cm, is functioning or is enlarging

14

how do you follow an incidentaloma?

need repeat imaging every 3 months for 1 year, then yearly

15

approach for adrenal CA resection

anterior approach for adrenal CA resection

16

Common metastases to adrenal

Lung CA (#1), breast CA, melanoma, renal CA

17

Management: cancer history with asymptomatic adrenal mass

Need biopsy

18

what if you have isolated metastases to the adrenal gland?

some isolated metastases to the adrenal gland can be resected with adrenalectomy

19

layers of the adrenal cortex

GFR = salt, sugar, sex steroids
- Glomerulosa: aldosterone
- Fasciculata: glucocorticoids
- Reticularis: androgens / estrogens

20

precursor for androgens / cortisol / aldosterone

cholesterol -> progesterone -> androgens/cortisol/aldosterone

21

what enzyme do all zones of the adrenal cortex contain?

all zones have 21- and 11-beta hydroxylase

22

Released from the hypothalamus and goes to anterior pituitary gland

Corticotropin-releasing hormone (CRH)

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Released from the anterior pituitary gland and causes the release of cortisol

ACTH

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Has a diurnal peak at 4-6 am

Cortisol

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Inotropic, chronotropic, and increases vascular resistance; proteolysis and gluconeogenesis; decreases inflammation

Cortisol

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Stimulates renal sodium resorption and secretion of potassium and hydrogen ion

Aldosterone

27

What stimulates aldosterone secretion?

Stimulates by angiotensin II and hyperkalmeia, and to some extent ACTH

28

What is significant of excess estrogens and androgens by adrenals?

Almost always cancer

29

Enzyme defect in cortisol synthesis

Congenital adrenal hyperplasia

30

- MCC congenital adrenal hyperplasia
- Precocious puberty in males
- Virilization in females
- Increased 17-OH progesterone leads to increased production of testosterone
- Is salt wasting (decreased sodium and increased potassium) and causes hypotension

21-hydroxylase deficiency (90%)

31

Tx: 21-hydroxylase deficiency

Cortisol, genitoplasty

32

HTN secondary to sodium retention without edema; hypokalemia; also have weakness, polydipsia, and polyuira

Hyperaldosteronism (Conn's syndrome)

33

#1 cause of primary hyperaldosteronism

Adenoma (85%)

34

Causes of primary hyperaldosteronism (Conn's syndrome)

Adenoma (85%), hyperplasia (15%), ovarian tumors (rare), cancer (rare)

35

Causes of secondary hyperaldosteronism (Conn's syndrome)

More common than primary disease
- CHF
- Renal artery stenosis
- Liver failure
- Bartter's syndrome (renin-secreting tumor

36

Dx for primary hyperaldosteronism

- Salt load suppression test (best, urine aldosterone will stay high)
- Aldosterone:renin ratio > 20
- Labs: low K, high Na, high urine K, metabolic alkalosis
- Plasma renin activity will be low

37

Localizing studies for hyperaldosteronism (Conn's syndrome)

MRI, NP-59 scintigraphy (shows hyper functioning adrenal tissue; differentiates adenoma from hyperplasia; 90% accurate); adrenal venous sampling if others nondiagnostic

38

What do you need to consider for pre-op optimization in hyperaldosteronism?

Pre-op need control of HTN and K replacement

39

Hyperaldosteronism: adenoma tx

Adrenalectomy

40

Hyperaldosteronism: hyperplasia treatment

Seldom cured (increased morbidity with bilateral resection)
- Try medial therapy first using spironolactone (inhibits aldosterone), calcium channel blockers, and potassium
- if bilateral resection is performed (usually done for refractory hypokalemia), patient will need fludrocortisone postoperatively

41

Adrenal insufficiency, Addison's disease

Hypocortisolism

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#1 cause hypocortisolism

Withdrawal of exogenous steroids

43

#1 primary disease: hypocortisolism

Autoimmune disease

44

Causes of hypocortisolism (Addison's disease)

Withdrawal of exogenous steroids (#1), pituitary disease, adrenal infection / hemorrhage / metastasis / resection

45

Causes decreased cortisol (ACTH will be high) and decreased aldosterone

Hypocortisolism (adrenal insufficiency, Addison's disease)

46

Dx: hypocortisolism (adrenal insufficiency, Addison's disease)

Cosyntropin test (ACTH given, urine cortisol measured) - cortisol will remain low

47

Hypotension, fever, lethargy, abdominal pain, nausea and vomiting, decreased glucose, increased K

Acute adrenal insufficiency

48

Tx: acute adrenal insufficiency

Dexamethasone, fluids, and give cosyntropin test (dexamethasone does not interfere with test)

49

Hyperpigmentation, weakness, weight loss, GI symptoms, increased K, decreased Na

Chronic adrenal insufficiency

50

Tx: chronic adrenal insufficiency

Corticosteroids

51

- Hypercortisolism
- Most commonly iatrogenic

Cushing's syndrome

52

Most sensitive test hypercortisolism (Cushing's syndrome)

24-hour urine cortisol

53

1st thing to do in hypercortisolism (Cushing's syndrome)

Measure 24-hour urine cortisol (most sensitive test) and ACTH

54

Hypercortisolism:
- Low ACTH
- high Cortisol

Patient has a cortisol secreting lesion (eg, adrenal adenoma, adrenal hyperplasia)

55

Hypercortisolism
- High ACTH
- High cortisol

Patient has a pituitary adenoma or an ectopic source of ACTH (e.g., small cell lung CA) -> move on to second part of workup (high-dose dexamethasone suppression test)

56

2nd portion of work up in hypercortisolism (high ACTH)

If ACTH is high, give high-dose dexamethasone suppression test
- if urine cortisol is suppressed -> pituitary adenoma
- if urine cortisol is not suppressed -> ectopic producer of ACTH (e.g. small cell lung ca

57

High dose dexamethasone suppression test:
- if urine cortisol is suppressed..

pituitary adenoma

58

High dose dexamethasone suppression test:
- if urine cortisol is not suppressed

Ectopic producer of ACTH (e.g. small cell lung CA)

59

Can help localize tumors and differentiate adrenal adenomas from hyperplasia

NP-59 scintography

60

#1 non-iatrogenic cause of Cushing's syndrome

Pituitary adenoma (Cushing's disease)
- 80% of cases

61

How will a pituitary adenoma look on low or high dose dexamethasone suppression test?

Cortisol should be suppressed with either or low or high dose dexamethasone suppression test

62

Pituitary adenomas: micro or maco?

Mostly microadenomas

63

How do you figure out which side of the pituitary is affected with a pituitary adenoma resulting in hypercortisolism?

Need petrosal sampling to figure out which side; MRI can also help

64

Tx: pituitary adenoma (Cushing's disease)

Most tumors removed with transsphenoidal approach; unresectable or residual tumors treated with XRT

65

#2 non-iatrogenic cause of Cushing's syndrome

Ectopic ACTH

66

What is ectopic ACTH most commonly from?

Small cell lung cancer

67

How will low- or high-dose dexamethasone suppression test look in ectopic ACTH production?

Cortisol is not suppressed with either low or high dose dexamethasone suppression test

68

How can you localize the lesion in ectopic ACTH production?

Chest and abdominal CT can help localize

69

Tx: Ectopic ACTH

Resection of primary if possible; medical suppression for inoperable lesions

70

#3 non-iatrogenic cause of Cushing's syndrome

Adrenal adenoma

71

Decreased ACTH, unregulated steroid production
- Tx: adrenalectomy

Adrenal adenoma

72

Tx: adrenal hyperplasia (macro or micro)

Metyrapone (blocks cortisol synthesis) and aminoglutethimide; bilateral adenalectomy if medical treatment fails

73

Rare cause of Cushing's syndrome

Adrenocortical carcinoma

74

Consider in patients with ectopic ACTH from tumor that is unresectable (would need to be a slow growing tumor - rare) or ACTH from pituitary adenoma that cannot be found

Bilateral adrenalectomy

75

When operating for Cushing's syndrome what is important post op?

Give steroids post op when operating for Cushing's syndrome

76

#1, #2, #3 causes Cushing's disease

1. Pituitary adenoma
2. Ectopic ACTH
3. Adrenal adenoma

77

Bimodal distribution (before age 5 and in the 5th decade); more common in females
- 50% are functioning tumors - cortisol, aldosterone, sex steroids
- Children display virilization 90% of the time (precocious puberty in boys, virilization in females); feminization in men; masculinization in women can occur
- Symptoms: abdominal pain, weight loss, weakness
- 80% have advanced disease at the time of diagnosis

Adrenocortical carcinoma

78

Tx: adrenocortical carcinoma

Radical adenalectomy; debulking helps symptoms, prolongs survival

79

5-year survival rate adrenocortical carcinoma

20%

80

From ectoderm neural crest cells

Adrenal medulla

81

Pathway of catecholamine production

Tyrosine -> dopa -> dopamine -> norepinephrine -> epinephrine

82

Rate limiting step (tyrosine to dopa)

Tyrosine hydroxylase

83

Enzyme that is an exclusive producer of epinephrine
- Only found in the adrenal medulla

PNMT (phenylethanolamine N-methyltransferase)

84

What does PNMT (phenylethanolamine N-methyltransferase)

Enzyme converts norepinephrine -> epinephrine
- Exclusively found in adrenal medulla, exclusive producer of epinephrine

85

What do adrenal pheochromocytoma produce?

Only adrenal pheochromocytomas will produce epinephrine

86

Breaks down catecholamines; converts norepinpehrine to normetanephrine, epinephrine to metanephrine

MAO (monoamine oxidase)

87

How is VMA (vanillylmandelic acid) produced?

Breakdown product of catecholamines (normetanephrine and metanephrine)

88

Where can you find extra-adrenal rests of neural crest tissue?

Usually in the retroperitoneum, most notably in the organ of Zuckerkandl at the aortic bifurcation

89

What is the origin of pheochromocytoma?

Chromaffin cells of the adrenal medulla

90

- Rare; usually slow growing; arise form sympathetic ganglia or ectopic neural crest cells
- Symptoms: HTN (frequently episodic), headache, diaphoresis, palpitations

Pheochromocytoma

91

What can pheochromocytoma be associated with?

MEN IIa, MEN IIb, von Recklinghausen's disease, tuberous sclerosis, Sturge-Weber disease

92

Laterality of pheochromocytoma

Right sided predominance

93

10% rule of pheochromocytoma

Malignant, bilateral, in children, familial, extra-adrenal

94

What is significant of extra-adrenal tumors in pheochromocytoma?

Extra-adrenal tumors are more likely malignant

95

Dx: pheochromocytoma

Urine metanephrines and VMA
- VMA most sensitize test for diagnosis
- MIBG scan (norepinephrine analogue) - can help identify location if having trouble finding tumor with CT scan / MRI
- Clonidine suppression test: tumor does not respond, keeps cathetcholamines increased
- No venography -> can cause hypertensive crisis

96

Most sensitize diagnostic test in pheochromocytoma

VMA

97

What is a MIBG scan?

MIBG (norepinephrine analogue) -> can help identify location if having trouble finding tumor with CT scan / MRI

98

How is the clonidine suppression test useful in pheochromocytoma?

Tumor does not respond, keeps catecholamines elevated

99

Why no venography in pheochromocytoma?

Can cause hypertensive crisis

100

Preoperative management of pheochromocytoma

Volume replacement and alpha-blocker first (phenoxybenzamine -> avoids hypertensive crisis); then B-blocker if patient has tachycardia or arrhythmias)

101

Why do you ALWAYS give alpha blocker before beta blocker in pheochromocytoma?

Can precipitate hypertensive crisis (unopposed alpha stimulation, can lead to stroke) and heart failure

102

Tx: pheochromocytoma

Adrenalectomy -> ligated adrenal veins first to avoid spilling catecholamines during tumor manipulation

103

How do you avoid spilling catecholamines during tumor manipulation in pheochromocytoma?

Ligate adrenal veins

104

Pheo: helps symptoms in patients with unresectable disease

Debulking

105

Inhibits tyrosine hydroxylase causing decreased synthesis of catecholamiens.

Metyrosine

106

What meds should you have ready during the time of surgery of pheochromocytoma?

Nipride, Neo-Synephrine, and anti arrhythmic agents (eg, amiodarone) ready during the time of surgery

107

Post op conditions to look for s/p adrenalectomy for pheochromocytoma

Persistent hypertension, hypotension, hypoglycemia, bronchospasm, arrhythmias, intracerebral hemorrhage, CHF, MI

108

Other sites of pheochromocytomas

Vertebral bodies, opposite adrenal gland, bladder, aortic bifurcation

109

Most common site of extra medullary tissue in pheochromocytoma

Organ of Zuckerkandl (inferior aorta near bifurcation)

110

What can cause falsely elevated VMA?

Coffee, tea, fruits, vanilla, iodine contrast, labetalol, alpha and beta blockers

111

Responsible for medullary CA of thyroid and extra-adrenal pheochromocytoma

Extra-medullary tissue

112

Rare, benign, asymptomatic tumor of neural crest origin in the adrenal medulla or sympathetic chain
- Tx: resection

Ganglioneuroma