B5.034 - CBCL Prework 1 Adrenal Incidentaloma Flashcards
what are the 3 layers of the adrenal cortex
zoma glomerulosa zona fasciculata zona reticularis
what is an adrenal incidentaloma
an adrenal mass >1cm discovered on accident
prevalence and characteristics of adrenal incidentalomas
4-6% increases with age most clinically non hyper-secreting benign 5% - cortisol producing 5% - pheos 1% - aldosterone producing 4% - carcinomas 2.5% - metastatic
primary symptoms of pheo
triad of headache, sweating, palpitations 1/2 have sustained HTN most of the remainder have paroxysmal spells
what is a pheo
a tumor that secretes excess catecholamines
rule of 10
for pheochromocytoma 10% bilateral, extraadrenal, above diaphragm, familial, malignant
lab Dx for pheo
elevated plasma fractionated metanephrines elevated urinary fractionated catecholamines, metanephrines, VMA presence of adrenal mass on CT
special techniques for dx of pheo
MIBG scan, pentetreotide, PET scan
treatment of pheo
surgical removal with pre op alpha blockers, followed by beta blockesr volume replacement
pheochromocytoma
pheo
note: lack of golgi and dark rings around cell
pathophysiology of cushings
excessive glucocorticoid exposure
clinical findings of cushings
truncal obesity
IGT/Diabetes ~2.5%
HTN
Hyperlipidemia
Coagulopathy
Osteoporosis
depression
hypogonadism
purple abdominal striae
proximal muscle weakness/wasting
central hypothyroidism
decreased growth velocity in children
how do you diagnose cushings
24 hr urinary cortisol >3x normal
Exogenous dexamethasone substitutes for endogenous cortisol in suppressing ACTH release
Late evening salivary cortisol
describe the dexamethasone test
1mg of dexamethasone at 11 PM to 12 AM and measurment of serum cortisol at 8 AM, should be less than 1.8
when do you do a pituitary MRI
after bichemical testing has confirmed cushings
pituitary MRI findings
a discrete adenoma will be visible in 35-65% of patients
10% of the population ages 20-40 have incidental tumors of pituitary
15% of pts with ectopic ACTH have abdnormal MRI
when do you refer a pt with cushings to surgery
if there is an unequivocal pituitary neoplasm on MRI >6mm in a patient without ectopic ACTH features
what is IPSS
Inferior petrosal sinus sampling
Bilateral simultaneous inferior petrosal sinus and peripheral venous sampling for ACTH levels before and after CRH stimulation
Compare rations of ACTH, if ration of sinus: periphery >3 its cushings disease
This is because it shows theres a tumor on the pituitary causing this, not carcinoid in the lung or something else
treatment of cushings
transphenoidal surgery to remove adenoma if pituitary
ketoconazole is an option if sugery is not
what is ketoconazole
non selective inhibitor of the adrenal and gonadal steroids
drug blocks multiple enzymes in cortisol pathway, can cause headaches, sedation and nausea, hepatotoxicity
management of cushings syndrome
adrenal adenoma - resecton
pituitary adenoma - transphenoidal resection
Ectopic ACTH - resection of tumor
Adrenal carcinoma - resection and chemo
what do you do if all options for cushing synrome fail
bilateral adrenalectomy
causes of aldosterone excess
primary aldosterone excess - high aldosterone, low renin
due to adrenocortical adenoma (conns)
bilateral idiopathic hyperaldosteronism
describe secondary hyperaldosteronism and causes
high aldosterone, high renin
renovascular hypertension, diuretic use, renin secreting tumors, LVHF
clinical features of hyperaldosteronism
HTN
hypokalemia, nocturia, muscle cramps, occasional severe muscle weakness, tetany, parasthesia
who gets screened for hyperaldosteronism
people with HTN and hypokalemia
HTN resistant to Rx or requiring multiple meds
incidental adrenal nodule on imaging
how do you screen for hyperaldosteronism
plasma aldosterone:plasma renin ration in AM
ratio >20 and plasma aldo level >15 with suppressed renin
confirm with oral salt loading or saline infusion test
or
24 hour urine for aldosterone and Na
describe the 24hr urine test for aldosterone
during test urine should have a Na excretion by 200
currently cutoff for Dx is 12 mcg/day of aldosterone production
how do you distinguish between adenoma vs bilateral adrena hyperplasia
adrenal imaging
if solitary unilateral >1cm in young pt under 40 do laparoscopic resection
adrenal vein sampling, if CT is normal or nodules <1cm or>40 years old, adrenal vein sampling is gold standard to determine if localized to one adrenal gland
treatment for hyperaldosteronism
goal is to decrease both the blood pressure and aldosterone levels
resection will cure in 30-60% of unilateral adenomas
BP meds can work if surgery isnt an option
what medications should be used to treat hyperaldosteronism
spironolactone
eplerenon
they are aldosterone receptor antagonists
what can cause bilateral masses
generally not endocrine
metastatic disease
lymphoma
infection
hemorrhage
endocrine causes of bilateral masses
ACTH depended cushings
bilateral pheo
bilateral primary hyperaldosteronoma
