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
Indication for parathyroidectomy:
Age?
Hypercalciuria value?
Renal dysfunction measured by what?
Calcium value?
What else?
Age? <50
Hypercalciuria value? >400 mg/24hrs (urine calcium/creatinine ratio <0.01 is hypocalciuric hypercalcemia)
Renal dysfunction measured by what? GFR <60 mL/min
Calcium value? 1 above normal
Kidney stones
Who gets radioactive iodine after thyroidectomy:
Size?
Degree of invasion?
Pts with moderate to high risk of recurrence. Basically
Any >4cm (>T2)
Any extrathyroidal/perithyroid tissue invasion
(+) Nodes
(+) Mets
Moderate risk:
- microscopic invasion into perithyroidal tissue
- cervical node met
- tumor with aggressive histology
- multifocal papillary thyroid microcarcinoma with extrathyroidal extension
High risk:
- macroscopic tumor invasion
- incomplete resection or gross residual disease
- distant Mets
Up to 5 nodes <0.2cm is okay.
What’s the difference between radical neck dissection vs modified radical
Radical:
- all nodes in I - V
- plus IJ, SCM, accessory nerve
Modified radical:
Same nodes but preserve 1 or 2 of the structures
Most common functional neuroendocrine tumor found in MEN 1?
Gastrinoma. 50% will develop zollinger ellison
Most common type of pancreatic neuroendocrine tumor outside of MEN syndrome?
Insulinoma
Why check vitamins D when working up hyperpara?
Because low vit D can induce compensatory high PTH
Small cell lung cancer pt. Hypercalcemia crisis. You give saline and bisphosphanates. What to give next? Why not lasix?
Calcitonin.
Calcitonin is particularly effective due to the rapidity of its effect. Renal calcium absorption is blocked and beneficial effects are seen as soon as 6 hours after administration.
These patients are severely volume depleted and lasix may worsen it and worsen the electrolyte derangement as well
What biochemical workup(s) is absolutely necessary for incidentaloma workup?
Dexa suppression
Plasma metanephrine
PRA/PAC is optional/reserved for hypokalemia/hypertension
All patients with adrenal incidentaloma should undergo screening for cortisol excess using a dexamethasone suppression test. All patients should be screened for pheochromocytoma using plasma-free metanephrines or urinary fractionated metanephrines. Screening for aldosteronoma using plasma aldosterone concentration and renin activity can be reserved for patients with hypertension and hypokalemia
Besides para, pituitary and pnet, what other tumor is associated with men1?
Foregut carcinoid
Papillary thyroid cancer survival. Under what age? What %
20yr survival for papillary thyroid CA >7cm
Under 65 at diagnosis = >90% survival (staging age is 55)
~50%
Defect when injuring superior laryngeal vs recurrent laryngeal?
Superior laryngeal: voice pitch
Recurrent laryngeal: hoarseness
Most common location of a parathyroid adenoma found during initial parathyroidectomy
Most common location of parathyroid adenoma during a reoperation if it was initially missed
Thyrothymic ligament
Tracheoesophageal groove
Up to what % of incidentally lit up thyroid nodules on PET are malignant? Do these tend to be primary thyroid lesions or Mets?
If you follow it up with ultrasound or CT and you don’t find a focal lesion, what does that mean?
Up to 21%. Primarily thyroid papillary carcinoma (95%) rest tend to be Mets.
If no corresponding focal lesion on US/CT then most likely benign