SECRETS Endo - Adrenals Flashcards
cushing syndrome sx
weakness amenorrhea deepening voice central obesity abdominal striae buffalo hump acanthosis nigricans
hyperglycemia
elevated random cortisol
cushing syndrome causes
iatrogenic glucocorticoids
cortisol-hypersecreting adrenal adenoma/carcinoma
ACTH-secreting pituitary adenoma
paraneoplastic secretion (small cell lung carcinoma)
cushing disease
elevated ACTH & cortisol
responsive to high dose dexamethasone
hypercortisolism - hyperglycermia
cortisol promotes hyperglycemia via ++ hepatic gluconeogenesis
mobilize aa from skeletal muscle (muscle wasting)
synthesis of gluconeogenic enzymes
hypercortisolism - hypertension
high plasma levels - cortisol is mineralocortic
hypernatremia, hypervolemia, hypokalemia
++ adrenergic receptors in vascular smooth muscle
normal plasma levels of cortisol - mineralocorticoid?
NO
sensitive tissues have 11B-hydroxysteroid dehydrogenase = metabolize cortisol
high levels = oversaturate 11B-HSD –> bind aldosterone receptors
licorice candy - cortisol
+++ cortisol
decrease activity of 11B-HSD
cortisol - bones
loss of bone density, osteoporosis
inhibit osteoblast, stimulate osteoclast
promote bone resorption
layers of adrenal cortex
Glomerulosa = mineralocorticoids Fasciculata = cortisol Reticularis = sex steroids
Medulla = NE, E
Nelson’s syndrome
diffuse hyperpigmentation due to + MSH production following bilateral adrenalectomy
++ ACTH/MSH production (from POMC) in pituitary
adrenal insufficiency sx
vague sx (weakness, malaise)
hyponatremia
hyperkalemia
hypoglycemia
hypotension
Addison’s disease & causes
primary adrenal insufficiency
due to autoimmune destruction, TB, metastatic invasion (lung cancer), disseminated fungal infections, drugs/iatrogenic steroids (ketoconazole, metyrapone)
cosyntropin
dx primary vs secondary adrenal insufficiency
blunted response = primary
normal response = secondary
Waterhouse-Friderichsen syndrome
bilateral adrenal hemorrhage
fatal
neisseria meningitidis
pheochromocytoma sx
headache
palpitations
profuse sweating
“impending doom”
intermittent episodes
why does HTN worsen with BB in pheochromocytoma?
epinephrine stimulates a & B adrenergic receptors
in presence of BB, will bind only a –> vasoconstriction
pheochromocytoma origin
neural crest derived chromaffin cells of adrenal medulla
use of clonidine in pheochromocytoma dx
differentiate from high stress state
central a2 agonist = inhibit sympa outflow
should reduce catecholamine production - if not, pheochromocytoma!
rule of 10s pheochromoctyoma
10% familial 10% extra adrenal 10% malignant 10% in kids 10% calcified 10% bilateral
familial pheochromocytoma
MEN IIa or IIb
VHL
neurofibromatosis
Neuroblastoma
neuroendocrine tumor
kids <5
hypertension
palpable abdominal mass
opsoclonus-myoclonus syndrome (chaotic eye movements)
mets to skin, bone, post mediastinum
N-myc oncogene
Homer-Wright rosettes
tx pheochromocytoma
a-blocker (zosin) FIRST then BB (olol)
surgery = give phenoxybenzamine FIRST
