21 Adrenal Flashcards
Blood supply to adrenal gland
Superior adrenal (inferior phrenic artery) Middle adrenal (aorta) Inferior adrenal (renal artery)
Superior adrenal artery
Inferior phrenic artery
Middle adrenal artery
Aorta
Inferior adrenal artery
Renal artery
Left adrenal vein goes to:
Left renal vein
Right adrenal vein goes to:
Inferior vena cava
Adrenal cortex innervation?
Nothing
Medulla innervation?
Sympathetic nervous system
Adrenal lymphatics
Subdiaphragmatic and renal lymph nodes
Incidentaloma
Seen in 1-2% of abdominal CT
5% are mets
Work up for incidentaloma
Check for functioning tumor: urine metanephrines, VMA< catecholamines, hydroxycorticosteroids, serum K with plasma renin/aldosterone
CXR
Colonoscopy
Mamography
Ominous characteristics for an incidentaloma
Non-homogenous >4-6cm Functioning Enlarging --> surgery
Common mets to adrenals
Lung CA
Breast CA
Melanoma
Renal CA
Cancer history with asymptomatic adrenal mass?
Biopsy
Adrenal cortex
From mesoderm
Glomerulosa - aldosterone
Fasciuclata - glucocorticoids
Reticularis - androgens/estrogens
Production of adrenal cortex hormones
Cholesterol -> progesterone -> androgens/cortisol/aldosteronew
All zones have 21- and 11-beta hydroxylase
Cortisol
Inotropic Chronotorpic Increases vascular resistance Proteolysis and gluconeogensis Decrease inflammation
Aldosterone
Stimulates renal sodium resoprtion and secretion of K+ and H+
Stimulated by angiotensin II an dhyperkalemia
Excess estrogen and androgen by adrenals?
Almost always cancer
21-hydroxylase deficiency
Precocious puberty in males, virilization in females
Salt wasting and hypotension
Tx: cortisol, genitoplasty
Excess 17-OH progesterone
11-hydroxylase deficiency
Precocious puberty in males, virilization in females
Salt saving - HTN
Tx: cortisol, genitoplasty
Excess deoxycortisone (acts as mineralcorticoid)
Hypertension without edema, hypokalemia, weakness, polydipsia, polyuria
Hyperaldosteronism (Conn’s syndrome)
Primary hyperaldosteronism
Low renin
Adenoma (85%), hyperplasia (15%), ovarian tumor (rare), cancer (rare)
Secondary hyperaldosteronism
Renin is high - more common than primary
CHF, renal artery stenosis, liver failure, diuretics
Batter’s syndrome (renin-secreting tumor)
Diagnosis for primary hyperaldosteronism
Salt-load suppression test (urine aldosterone will stay high)
Aldosterone:renin ration >20
Labs: decreased K+, increased Na, increased urine K, metabolic alkalosis
Plasma renin activity will be low
Localizing studies for hyperaldosteronism
MRI
NP-59 scintigraphy (hyperfunctional adrenal tissue - differentiates adenoma from hyperplasia - 90% accurate)
Adrenal venous sampling
What do you need to fix preoperative for hyperaldosteronism?
Hypertension
Hypokalemia
Treatment for hyperaldosteronism secondary to an adenoma?
Adrenalectomy
Treatment for hyperaldosteronism secondary to hyperplasia
Medical therapy - spironolactone, CCB, potassium supplementation
Bilateral resection only done for refractory hypokalemia (increased morbidity) - need fludrocortisone postop
Hypocortisolism
Adrenal insufficiency, Addison’s disease
MCC - withdrawal of exogenous steroids
MCC primary disease - autoimmune destruction
Other - pituitary disease, infection/hemorrhage/metastasis/resection
Low cortisol, high ACTH, low adosterone
Dx: Cosyntropin test (give ACTH, measure urine cortisol - positive if it stays low)
Acute adrenal insufficiency
Hypotension, fever, lethargy, abdominal pain, nausea, vomiting
Decreased glucose, increased potassium
Tx: Dexamethasone, fluids
Confirmation: cosyntropin test (dexamethasone does not interfere)
Chronic adrenal insufficiency
Hyperpigmentation, weakness, weight loss, GI symptoms
Increased potassium, decreased sodium
Tx: Corticosteroids
Hypercortisolism
Cushing’s syndrome
MCC - iatrogenic
- Measure 24-hr urine cortisol and ACTH
If high cortisol, with low ACTH - cortisol secreting lesion (done)
If high cortisol, with high ACTH - ACTH secreting lesion;
Then do High-dose dexamethasone suppression test:
- Urine cortisol suppressed - pituitary adenoma
- Not suppressed - ectopic producer of ACTH
In hypercortisolism - how do you localize tumors and differentiate adrenal adenomas from hyperplasia?
NP-59 scintography
Pituitary adenoma
Cushing's disease Cortisol is NON-suppressable Microadenoma Localization - petrosal sampling, MRI Tx: transsphenoiodal, XRT
Ectopic ACTH
MCC small cell lung CA
Cortisol is NON-suppressable
Localization - chest and abdominal CT
Tx: Resection
Adrenal adenoma (cushing’s syndrome)
Decreased ACTH - unregulated steroid production
Tx: Adrenalectomy
Adrenal hyperplasia (cushing’s syndrome)
Medical tx:
- Metyrapone (blocks cortisol synthesis)
- Aminoglutethimide (inhibits steroid production)
Bilateral adrenalectomy is medical treatment fails
Adrenocortical carcinoma
Before 5yo, after 50yo, more common in females
50% functioning - cortisol, aldosterone, sex steroids
Viralization, androgeny
Sx: abdominal pain, weight loss, weakness
Tx: Radical adrenalectomy, debulking
- Mitatane (adrenal-lytic) - residual, recurrent, metastatic
Catecholamine production
Tyrosine > dopa > dopamine > NE > Epi
Rate limiting step for catecholamine production?
Tyrosine hydroxylase
Origin of adrenal medulla?
Ectoderm - neural crest cells
Why can Epi only be produced in adrenal medulla?
PNMT (phenylethanolamine N-methyltransferase)
Converts NE to EPi
Only found in adrenal medulla
What breaks down catecholamines?
Monoamine oxidase (MAO)
NE > normetanephrine
EPI > metanephrine
Then turned into vanillylmandelic acid (VMA)
Extra-adrenal rests of neural crest tissue locations?
Retroperitoneum
Organ of Zuckerkandl at the aortic bifurcation
Pheochromocytoma - 10% rule
Malignant, bilateral, in children, familial, extra-adrenal
Pheochromocytoma - associated syndromes
MEN IIa MEN IIb ZVon Recklinghausen's disease Tuberous sclerosis Struge-Weber disease
Pheochromocytoma - symptoms
HTN (episodic)
Headache
Diaphoresis
Palpitations
Pheochromocytoma - Diagnosis
Urine metanephrines and VMA*
MIBG scan (NE analogue) (localization)
Clonidine suppression test (tumor does NOT respond)
DO NOT DO venography - can cause HTN crisis
Pheochromocytoma - preoperative treatment
Volume replacement
A-blocker first (phenoxybenzamine)
then B-blocker (if needed for tachcyardia or arrhythmias)
What happens if you don’t alpha blockade before giving a pheo b-blocker?
Unoppsed alpha stimulation –> HTN crisis, stroke, heart failure
Pheochromocytoma - treatment?
Adrenalectomy - ligate adrenal veins first to avoid spilling catecholamines during tumor manipulation
Metyrosine - inhibits tyrosine hydroxylase\
Have ready - Nipride, Neo-=synephrine, antiarrhythmic agents (just in case)
Post-op conditions associated with Pheochromocytoma?
Persistent HTN Hypotension Hyperglecmia Bronchospasm Arrhythmias Intracerebral hemorrhage CHF MI
Other sites of pheo?
Organ of zuckerland (most common - inferior aorta near bifurcation)
Vertebral bodies
Opposite adrenal gland
Bladder
What can cause falsely elevated VMA?
Coffee Tea Fruits Vanilla Iodine contrast Labetalol A- and b-blockers
Ganglioneuroma
Rare
Benign
Asymptomatic tumor of neural crest origin in adrenal medulla or sympathetic chain
Tx: Resection
