Adrenal Flashcards
Adrenal: arterial supply, venous drainage, innervation, lymphatics
-Superior adrenal: inferior phrenic a.
-Middle adrenal: aorta
-Inferior adrenal: renal a.
-L adrenal v.: drains into L renal vein
-R adrenal v.: drains into IVC
-Cortex: no innervation
-Medulla: Sympathetic splanchnic
-Lymphatics: drain to subdiaphragmatic & renal lymphatics
Adrenal anatomy
-Adrenal Cortex (Mesoderm) + Medulla (Ectoderm)
-Neuroendocrine in origin chromaffin cells
-Zona Glomerulosa: “Salt” – regulates aldosterone
-Zona Fasicularis: “Sugar”- glucocorticoids
-Zona Reticularis: “Sex”- androgens/estrogen
Incidentaloma
-MC benign, non-functional2
*Rule out cortisol tumor: Low dose dexamethasone suppression test
*Rule out Pheo: Plasma metanephrines
*ONLY HYPERTENSIVE OR HYPOKALEMIC rule out Conn’s: Aldosterone:renin ratio > 25
-Less than 4 cm non-functional: repeat CT in 3-6 months then annually for 2 years. Repeat biochemical testing annually for 5 years.
-Greater than 4 cm, functioning, greater than 10 HU (high attenuation), enlarging: adrenalectomy
-MC mets to adrenal: #1 lung, breast, melanoma, renal CA
-CA hx w asx adrenal mass: FNA if it will change management. If you are already planning on adrenalectomy, then no point
-FNA cannot differentiate between benign and malignant; only differentiates between adrenal or metastatic lesion
-R/o pheochromocytoma prior to biopsy to prevent hypertensive crisis
Nelson’s syndrome
-S/p BL adrenalectomy; ACTH secretion from recurrent pituitary tumor growth
-Pituitary enlargement compresses optic nerve (vision issues) and hyperpigmentation. 2/2 to chronic CRH stimulation
-Tx: External beam radiation
Tyrosine-> -> -> -> epi
Rate limiting step
-Tyrosine-> dopa-> dopamine -> norepi -> epi
-Tyrosine hydroxylase – rate limiting step (tyrosine -> Dopa)
Benign adrenal mass
-Less than 10 HU
-Washout > 50% @ 10 minutes= lipid rich
-Smooth, homogenous
Laparoscopic adrenalectomy should be performed for:
-Small and medium functional and benign adrenal tumor
-Contraindicated in malignancy (local invasion, LN mets)
-Open adrenalectomy preferred for > 6 cm tumor
Laparoscopic right adrenalectomy from a lateral approach: 1st step= divide right triangular ligament to mobilize right lobe of the liver -> retraction of liver & exposure of retroperitoneum. Mobilization of the hepatic flexure of the colon may also be needed
Conn’s syndrome
Most common functional tumor
MCC is bilateral hyperplasia!! Not adenoma
* Get a metabolic alkalosis
* Stop all ACE, diuretics, spironolactone
* 1st screen with plasma Aldosterone to plasma renin activity ratio > 20 or 30 = positive
* Then confirm with salt load suppression test and measure 24-hour urine aldosterone > 12 = diagnostic
* Then get CT
* Adrenal vein sampling – Most accurate test for localizing, and differentiating BTWN Adenoma and hyperplasia
- SESAP says its needed for all workup for surgery. CT is commonly incorrect.
- Need to always get this for the following to differentiate between adenoma and hyperplasia
1. Normal CT without mass
2. Patients > 35!!! Key.
3. BL adrenal nodularity
4. Unilateral nodule < 1 cm
* If adenoma adrenalectomy
* Hyperplasia spironolactone or eplerenone. If fails BL Adrenalectomy
* Bartter syndrome – Renin secreting tumor
-1ary aldosteronism/ Conn’s syndrome: hypokalemia, hypernatremia, metabolic alkalosis, elevated urinary potassium, plasma aldosterone: renin activity ratio >25
-HTN refractory to medical therapy= workup
Cushing’s Syndrome
When operating for cushings, need post op hydrocortisone
Subclinical cushings no overt clinical signs but biochemical workup = positive. adrenalectomy
Diagnosis:
* SESAP says dexamethasone suppression test no longer used and provides a different workup
- Screen with urinary free cortisol, if high
- Confirm with plasma corticotropin level (PCL) ratio: obtain PCL ratio by inferior petrosal sinus / peripheral vein PCL central to peripheral ratio
- if > 3 then this is Cushing’s Disease MRI brain
- If < 3 then this is ACTH producing tumor from lung small cell cancer CT chest
- If corticotropin levels are not measurable adrenal tumor CT abdomen
* Screening - Late night salivary cortisol X 3 – Is more accurate than serum cortisol
* Best Initial Screening test: 24H urine cortisol If high then do below
* Screening - Low dose 1 mg Dexamethasone suppression test and check am serum cortisol
- If cortisol is suppressed = ruled out Cushing’s Syndrome
- If cortisol not suppressed = You have diagnosed Cushing’s syndrome
* Next check ACTH
* Low ACTH = adrenal source Next step CT scan abdomen
* High ACTH = pituitary or ectopic (small cell lung CA) high dose dexamethasone test if suppressed = Cushing’s disease Perform MRI brain
- If not suppressed Small cell CA CT chest
The most common cause of Cushing syndrome: steroids; endogenous: ACTH pituitary adenoma
Cushing disease (pituitary)
-Cushing disease, by definition= ACTH-secreting pituitary adenoma- most resected completely with trans-sphenoidal microsurgery; cortisol levels will be suppressed by high-dose dexamethasone suppression tests
Cushing disease (pituitary) MC non-iatrogenic cause of cushings syndrome Tx: transsphenoidal resection. Unresectable or residual is XRT
* MRI – best initial test to localize.
- These are microadenomas (< 1 cm)
- If unable to localize or no mass seen, then you must do below before surgery
* Petrosal sampling – Most accurate test to localize
Ectopic ACTH – Small cell or others
- Treatment is surgical excision
Adrenal cushing Hyperplasia MC Treatment:
- If patient has over symptoms of cushings BL adrenalaectomy
- Can also try metyrapone and aminoglutethimide, If it fails then BL adrenalectomy
Adrenal cushings adenoma. Tx: adrenalectomy. Will need stress dose steroids
* NP59 scintigraphy Best test for either equivocal CT or suspected hyperplasia. Differentiates hyperplasia vs adenoma
BL adrenalectomy for: ectopic ACTH tumor that’s unresectable OR ACTH tumor from pituitary that can’t be found
* Need hydrocortisone and fludrocortisone post op
Pheochromocytoma
Pheochromocytoma (paraganglioma = pheo just not in adrenal gland)
MC benign
Risk of malignancy is not based upon histology/mitosis, it is based on local invasion and presence of mets
MC right sided
Familial tumor is less likely to be malignant, but more likely to be bilateral
10% rule malignant, BL, children, familial, extra-adrenal
NF-1, VHL
Extra adrenal = more likely to be CA
Diagnosis:
- Plasma metanephrines – used as a screening tool, has highest sensitivity
- Urine VMA is no longer used due to low specificity
- Get 24-hour urine catecholamines/metanephrines to confirm the diagnosis – higher specificity
- MRI abdomen best
MIBG – (NO LONGER used for localization) this has been replaced by MRI to localize
Remember: never start b-blocker first. The order should be phenoxybenzamine 1st THEN Labetalol (only if needed). Don’t want unopposed alpha agonism
Pre-op phenoxybenzamine 10 mg BID 2 weeks prior, then high salt diet 3 days after starting that. 1-2 liters of NS day before surgery reduces hypotension intra-op
Pheo adrenalectomy, even if there is evidence of mets.
- For recurrence or metastatic disease especially disease that secrete catecholamines, reoperation is BEST especially if you can achieve R0 or R1 resection or debulk for actively secreting tumor as a palliative measure
Metastatic disease – can get chemo or radioactive I-MIBG
Metyrosine – inhibits tyrosine hydroxylase and decreases catecholamines given preop or for metastatic disease
Adrenocortical Cancer
60% are functional!!!!
MC Secrete cortisol. Present in most patients
Needs biochemical work up before surgery
Mets is a contraindication to resection
Extension of tumor into IVC or renal vein does not preclude resection
Bimodal
Excess androgens and estrogens from adrenal glands is almost always adrenal CANCER
Usually diagnosed/suggested on CT/MRI shows: local invasion, calcifications, necrosis or hemorrhage
Work up: CT chest/abd/pelvis for staging
Tx: En bloc R0 resection, adrenalectomy, open anterior approach
- Add adjuvant Mitotane for high rade
Mitotane – for residual, recurrent, or metastatic adrenal cancer
Adrenal insufficiency
most sensitive test in cosyntropin test. Dx: if baseline cortisol < 15 or if increase in cortisol is <9 = positive
Primary adrenal insufficiency – MCC is autoimmune
Secondary adrenal insufficiency – MCC is exogenous use
Tx: dexamethasone initially because doesn’t interfere with test
Chronic tx: hydrocortisone and fludocortisone
Fever, N/V, abdominal pain, hypotension after thymectomy for myasthenia gravis or splenectomy for ITP Addisonian crisis give dexamethasone
-Fever, hypotension (not responding to IV fluid), hypoglycemia, hyperkalemia. If ACTH stimulation test given, correlating urinary & blood cortisol levels would not rise as they normally should
-1ary: MC= autoimmune atrophy of adrenal glands; HIV, CMV, metastases less common causes
-2ary: exogenous corticosteroid use (eg SLE), MC overall
-Hyponatremia: lack of aldosterone & release of excess antidiuretic hormone (ADH). Aldosterone inc sodium reabsorption & potassium excretion in the kidney. Hypotension stimulates release of ADH= free water absorption -> worse hyponatremia
-Suspected acute adrenal insufficiency (eg refractory hypotension requiring vasopressors despite appropriate resuscitation and antibiotics) should be empirically supplemented with IV glucocorticoids (eg, hydrocortisone, dexamethasone). Confirmatory testing is not required nor should treatment be delayed in the acute setting
Steroid prophylaxis for patient on chronic steroids
Only need to give steroid px if taking > 10 mg a day
Moderate risk procedures – 50 mg bolus of hydrocortisone then 25 mg Q8 X 1 day. Then taper to normal dose
High risk surgery – 100 mg bolus then 50 mg q8 X 1 day then taper
Congenital Adrenal Hyperplasia
-21 hydroxylase deficiency: increased testosterone and decreased aldosterone
-11 hydroxylase deficiency: increased testosterone and increased aldosterone
-17 hydroxylase deficiency: decreased testosterone and increased aldosterone
Functional adrenal biochemical work
Adrenal imaging
