Chapter 21: Adrenal Flashcards
1
Q
vascular supply: superior adrenal
A
inferior phrenic artery
2
Q
vascular supply: middle adrenal
A
aorta
3
Q
vascular supply: inferior adrenal
A
renal artery
4
Q
drainage of left adrenal vein
A
left renal vein
5
Q
drainage of right adrenal vein
A
inferior vena cava
6
Q
Innervation of medulla
A
sympathetic splanchnic nerve
7
Q
innervation of adrenal cortex
A
no innervation of adrenal cortex
8
Q
lymphatic drainage of adrenal
A
lymphatics drain to subdiaphragmatic and renal lymph nodes
9
Q
what makes up the adrenals
A
made up of adrenal cortex and adrenal medulla
10
Q
incidence of incidentaloma of adrenal mass on CT scan
A
1%-2% of abdominal CT scans show incidentaloma (5% are metastases)
11
Q
two things to know about asymptomatic adrenal masses
A
- benign adenomas are common
- adrenals are also common site for metastases
12
Q
what to do when you see an asymptomatic adrenal mass?
A
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
Q
when is surgery indicated for asymptomatic adrenal mass?
A
ominous characteristics (non-homogenous), is > 4-6 cm, is functioning or is enlarging
14
Q
how do you follow an incidentaloma?
A
need repeat imaging every 3 months for 1 year, then yearly
15
Q
approach for adrenal CA resection
A
anterior approach for adrenal CA resection
16
Q
Common metastases to adrenal
A
Lung CA (#1), breast CA, melanoma, renal CA
17
Q
Management: cancer history with asymptomatic adrenal mass
A
Need biopsy
18
Q
what if you have isolated metastases to the adrenal gland?
A
some isolated metastases to the adrenal gland can be resected with adrenalectomy
19
Q
layers of the adrenal cortex
A
GFR = salt, sugar, sex steroids
- Glomerulosa: aldosterone
- Fasciculata: glucocorticoids
- Reticularis: androgens / estrogens
20
Q
precursor for androgens / cortisol / aldosterone
A
cholesterol -> progesterone -> androgens/cortisol/aldosterone
21
Q
what enzyme do all zones of the adrenal cortex contain?
A
all zones have 21- and 11-beta hydroxylase
22
Q
Released from the hypothalamus and goes to anterior pituitary gland
A
Corticotropin-releasing hormone (CRH)
23
Q
Released from the anterior pituitary gland and causes the release of cortisol
A
ACTH
24
Q
Has a diurnal peak at 4-6 am
A
Cortisol
25
Inotropic, chronotropic, and increases vascular resistance; proteolysis and gluconeogenesis; decreases inflammation
Cortisol
26
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
42
#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
