Chapter 21 - Adrenal Flashcards
Arteries to adrenals and where they come from
Superior adrenal from inferior phrenic artery
Middle adrenal from aorta
Inferior adrenal from renal artery
Adrenal veins from where
R from IVC
L from renal vein
Layers of adrenal and embryonic derivation
Medulla is deep - from ectoderm (neural crest??)
Cortex is mesoderm
Which part of adrenal has ‘GFR’ layers? Deep or superficial?
Cortex does which is superficial to the medulla
Layers of cortex and what they secrete
Glomerulosa - aldosterone
Fasciculata- cortisol
Reticularis - androgen
Innervation to adrenals by layer
Cortex none
Medulla sympathetic splanchnic nerves
How many CT scans show adrenal incidentaloma
What percentage are mets
1-2%
5%
First step when adrenal mass is found
Check for functionality (DONT biopsy first).
Labs to check for functionality
*** not 100% on this but for now
- For pheo: 24 hour urine catecholamines (spec) or plasma metaneph (sens)
- For Cushing: low dose dex then confirm with either 24 hour cortisol or late night salivary cortisol
- For Conn(?): serum to aldo:renin ratio (high aldo low renin is suggestive, 20x). Adrenal vein sampling to localize mass.
You can also do a salt load suppression test which is best (urine aldo stays high)
How do you do low dose dex suppression test
Give 1mg oral at 11-midnight
Test cortisol level before 10 am
Step two after adrenaloma
Family history
May want to look for primary
INDICATIONS FOR SURGERY WITH ADRENAL MASS - CT scan
KNOW THESE
- non homogenous
- > 4-6 cm
- functioning
- enlarging
How to just follow the incidentaloma
CT every three months for a year then yearly
Common mets to adrenals
Lung, breast, melanoma, renal
Cancer hx w assymptomatic renal mass
BIOPSY
Cortisol feedback loop
Hypothal: CRH
Pituitary: ACTH
adrenal cortex fascic: cortisol which has negative feedback on CRH production
What makes androgens/cortisol/aldo
Cholesterol> progesterone
Action of aldosterone
Stimulates Renal sodium resorption and secretion of potassium and hydrogen ion
What normal stimulates aldosterone secretion
Angiotensin II and hyperkalemia
Almost always cancer if mass is secreting
Estrogens and androgens
Benign adrenal mass findings
HU < 10 +
<4 cm +
Non functioning +
Washout >50% (more fat) +
Symptoms of hyperaldosteronism
- HTN secondary to NA retention without edema
- hypokalemia
- weakness
- polydipsia
- polyuria
Causes of primary aldosteronism (aldo is just high on its own)
Aldo secreting adenoma makes up 85%
Other stuff- hyperplasia, Ovarian tumors and cancer are rare
Causes of secondary hyperaldosteronism
Renin is also high (more common than primary)
CHF, renal artery stenosis, liver failure, diuretics, barrters syndrome (renin rumor)
Best tests in order of better for diagnosing primary hyperaldosteronism
- Salt load suppression test, urine aldosterone will stay high
- Aldosterone to renin ratio over 20
Labs in Conn syndrome (hyperaldosteronism)
Low K High Na High urine K Metabolic alkalosis (bc hydrogen ions)** Low renin
How to treat hyperaldo from hyperplasia
Not localized so try
Spironolactone
Calcium channel blockers
Potassium
Na restriction
If you do bilateral adrenalectomy, need fludricortisone
RAAS PATHWAY triggers
Stems from decreased intravascular volume and decreased sodium concentration
Most common causes of high cortisol in order - top 4
- Iatrogenic
- Pituitary adenoma (Cushing disease)
- Ectopic ACTH (usually small cell lung cancer)
- Adrenal adenoma
Symptoms of Cushing syndrome
Obesity Muscle weakness Fatigue Hirsutism Osteopenia Moon facies Striae Buffalo hump
