Endocrine Flashcards
Pheo
What’s the best screening test?
What’s the tumor marker?
Screening: plasma-free metanephrines
Tumor marker: chromogranin A
For prepping someone for pheo surgery you do alpha blockade and then what else?
When do you know when you’ve alpha blockaded enough?
Replete fluid because they’re gonna be vasoconstricted due to alpha blockade -> low BP, overall hypovolemic.
Enough blockade when they’re dizzy. Orthostatic hypotension
Adrenal tumor is likely benign if Hounsfield unit is what?
<10 (74% sensitivity)
What is Conn syndrome?
What is Addison’s disease?
What is Cushing’s disease vs syndrome?
Conn: primary hyperaldo
Addison disease: primary adrenal insufficiency or hypocortisolism
Cushing disease: pituitary. Syndrome: adrenal
What to do with incidentaloma?
Test functions on all of them
<4cm: watch unless functional.
> 4cm: cut it out after functional studues
Right vs left adrenalectomy what to watch out for?
Adrenal vein on the right sometimes goes directly into the IVC. makes your sphincters tight.
Left adrenal vein -> renal vein
What two tests are you going to order if you’re suspecting aldosteronoma?
How do you interpret the result?
PAC: Plasma Aldosterone Concentration
PRA: Plasma Renin Activity
PAC/PRA > 25-30
PAC > 15 ng/dl
PRA < 1ng/ml
When do you do adrenal vein sampling? What’s the purpose of doing this?
if no adrenal vein sampling, what % of the people get an unnecessary operation?
For Conn syndrome. Hyperaldosteronism. Even if CT shows a unilateral adrenal lesion you have to do the sampling because oftentimes it’s a bilateral secretion issue. If bilateral -> spironolactone or eplerenone.
If no adrenal vein sampling -> 20-25% ppl may undergo unnecessary adrenalectomy
When is MIBG appropriate to obtain?
For pheo
In someone with biochemical dx of pheo with bilateral adrenal masses
Or when you suspect metastatic disease
Adrenal cortical carcinoma
What percentage of them are functional?
What’s the most common type? What percentage?
More than 50% are functional
30-40% are cortisol secreting
How do you interpret the information you get from 24hr urine calcium?
24hr urine calcium/creatinine ratio <0.01 = familial hypocalciuric hypercalcemia
24hr urine calcium > 400 is an indication for parathyroidectomy
Incidence of incidentaloma?
What % of incidentalomas are functional?
1-4% of all abdominal CT
About 20% are functional
What % of pheo has a genetic predisposition?
~25%
Adrenal incidentaloma is found on a trauma scan. Pt is in your endocrine surgery office for a follow-up.
1) first what do you do? To look for what?
2) how do you interpret this test?
Who needs functional workup? What are they?
1) adrenal protocol CT.
Non-com CT is followed by rapid injection of contrast and then 60 seconds later a contrast CT is performed. Then a delayed scan is obtained 15 min later.
1.5) benign adrenal cortical adenomas: <10 Hounsfield unit on non-con. >60% contrast washout -> indicates a lipid mass
Everybody needs functional workup regardless of the size.
- plasma aldo, plasma Renin
- low dose dexa suppression test, ACTH
- metanephrines
You’re about to do an adrenalectomy. Is there a size limit to forego laparoscopic approach and go straight to open?
When else do you do open?
8cm
Or imaging suspicious for malignancy
You’re about to do an adrenalectomy for Cushing syndrome. What do you need to give preoperatively? Why?
Stress dose steroids. The contralateral adrenal gland had been suppressed because of HPA (hypothalamic-pituitary-adrenal) axis
You’re about to operate on an aldosteronoma. What do you need to give preoperatively?
Aldosterone antagonist like spironolactone or eplerenone for BP control and potassium retention
Which interleukin does cortisol stimulate?
IL-10 (anti-inflammatory factor)
What is the mechanism of action of Grave’s disease?
How is hyperfunctioning thyroid adenoma different from Grave’s disease in terms of symptoms?
Autoantibodies binding to the TSH receptor
anti-thyroglobulin
Adenoma will not cause exopthalmos
What’s the gastrinoma triangle
Where cystic duct meets common hepatic duct
2nd portion of the duodenum
Neck of the pancreas
What pancreatic neuroendocrine tumor is primarily in the tail of the pancreas?
VIPoma and glucagonoma
Which pancreatic neuroendocrine tumor is evenly distributed among the whole pancreas?
Insulinoma
Which pancreatic neuroendocrine tumor is located primarily at the head of the pancreas?
Somatostatinoma
Biopsy or survey thyroid nodule?
- 7cm thyroid nodule
- 2cm hypoechogenic nodule
- 6cm cystic nodule
Nodule <1cm: US surveillance in 6 months
Nodule between 1-1.5cm: FNA if suspicious features such as solid nodule, microcalcification, hypervascularity, taller than wide, irregular borders. If low risk features, can watch
> 1.5cm: FNA