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
Primary hyperpara. What should the chloride:phosphate ratio be?
ratio > 33 = supports primary hyperpara
What % of medullary thyroid cancer is genetic?
25F, 1.5cm thyroid nodules. Shows medullary cells. Minimum required surgery?
What if there’s measurable calcitonin lvl post-op?
Radioactive iodine or not?
20% genetic, 80% sporadic
Total thyroid + CENTRAL neck dissection
If (+) calcitonin lvl -> imaging. It could be met
they can actually be elevated for week.
Medullary cells do not concentrate iodine. So radioactive iodine is not useful for these ppl
Effect of parathyroidectomy on bone mineral density at 2 yrs vs 5-8 yrs
what % risk reduction for hip fx?
It improves at 2 years
At 5-8 years it’s lower than baseline regardless of surgery or observation. But with parathyroidectomy the decrease is less severe
64% risk reduction for hip fx
24% risk reduction for all fx
What % of pts referred for parathyroidectomy are asymptomatic?
Does in depth neuropsychiatric testing revealed more symptoms?
Does parathyroidectomy improve cardiovascular risks?
> 80% because most are now detected on routine screening labs
In depth neuropsychiatric testing is nonspecific and not used
Parathyroidectomy doesn’t really improve cardiovascular risks
Sodium and potassium in conn syndrome vs addison disease?
Addison disease: adrenal insufficiency. Normal aldosterone -> absorb sodium and excrete K. Lack of it -> hyponatremia, hyperkalemia
Conn syndrome: primary hyperaldo -> absorb Na like crazy excrete K -> hypernatremia, hypokalemia
How does addison disease cause dark skin?
Addison disease: adrenal insufficiency.
No cortisol -> hypothalamus secretes CRH like crazy
Pituitary secretes ACTH like crazy.
ACTH has melanin stimulating hormone like acitivity
What is the T staging for thyroid cancer?
T1: <2 cm
T2: 2-4 cm
T3: >4 cm
T4: any extrathyroid involvement
How do you stage papillary thyroid cancer?
Under 55, all and any thyroid cancer is stage I or II
Stage I: any T, any N, M0
Stage II: any T, any N, M1
T1 :<2cm
T2: 2-4cm
T3: >4cm
T4: invades perithyroidal tissue
What is a normal chloride to phosphate ratio?
Poor man’s way to assess pth.
If chloride > 33 x phosphate then hyperpara
What is the most common reason to operate on pts with secondary hyperparathyroidism?
Severe bone pain not responsive to medical management
What are the borders of the central neck node dissection?
hyoid bone superiorly
Carotid arteries laterally
Superficial layer of the deep cervical fascia anteriorly
Deep layer of the deep cervical fascia posteriorly
Innominate artery on the right and its corresponding axial plane on the left inferiorly
Thyroid nodule FNA -> shows follicular lesion of unknown significance. Next step?
repeat FNA for gene expression classifier testing.
High negative predictive value for cancer.
Postintubation tracheal stenosis (PITS)
What is the incidence? how long after intubation does it usually occur?
When do symptoms appear time wise and diameter wise?
Treatment?
About 1-2%
Usually within 3-6 weeks. <10mm exertional dyspnea. <5mm stridor
Rx: tracheal rxn
Treatment for medullary thyroid cancer?
Total thyroid + b/l central lymph node dissection
+ Modified radical neck dissection. For any palpable/biopsy proven lateral neck disease
Treatment for medullary thyroid cancer if there is distant disease?
Surgery limited to bulk resection for functional preservation and locoregional disease control
expected benefit of parathyroidectomy
- does bone density improve?
- does fracture rate improve?
- kidney stones?
- hypertension?
- kidney function?
1) Bone density improvement and decreased fracture rate
2) formation of less kidney stones
3) psychologic
HTN almost never resolves
Kidney function that’s already impaired does not improve after parathyroidectomy
What is the earliest manifestation of disease in MEN1?
hyperpara
For MEN 1 hyperpara, is it usually a single adenoma or 4 glad hyperplasia?
4 gland hyperplasia
What is the most commonly manifested disease in MEN1?
Hyperpara
For MEN1, among the PNETs, which one is the most common?
Gastrinoma
Insulinoma is second most common
For non MEN, insulinoma is the most common overall
For MEN1 pituitary adenoma they tend to me microadenomas or large lesions?
Large lesions. They cause both prolactin hypersecretion and optic chiasm
How to make the decision for recurrent nerve reconstruction for thyroid cancer?
If the nerve is already paralyzed, then recon not helpful
For medullary thyroid cancer calcitonin lvl above what should prompt a metastatic workup?
Calcitonin > 400
Thyroid cancer and neoadjuvant therapy?
Only when dealing with anaplastic
75M right lateral neck mass. FNA shows papillary thyroid cancer. What to do?
Total thyroid + right modified radical neck dissection
What does a supernumerary parathyroid gland mean?
Where is its most common location?
Additional glands on top of the normal 4
Cervical thymus
ADH vs aldosterone in terms of:
- Where they are made
- vasoconstriction?
- target site and how it works
Vasopressin = ADH
ADH: made in hypothalamus, secreted by posterior pituitary
Aldo: adrenal cortex. Zona glomerulosa
ADH: vasoconstricts
Aldo: does NOT vasoconstrict
ADH: works in distal tubules. Makes free water absorption
Aldo: absorbs sodium (and water)
In the OR with pheo. Well controlled BP preop with alpha blockade. Now 230/110 what to do?
Use short acting, easily titratable drug like nicardipine or nitroprusside
What is the primary good prognostic factor for resection if an isolated met to adrenal gland?
Disease free interval between initial cancer and met > 6 mo. is good prognostic indicator
Blood supply to the left adrenal gland vs right adrenal gland
Left adrenal gland
- superior adrenal artery: from inferior phrenic artery
- middle adrenal artery: from the aorta
- inferior adrenal artery: from the renal
Right adrenal is the same.
For MEN IIA and IIB, when should they undergo thyroidectomy?
Do you have do to neck dissection ?
IIA: before 5 yrs old
IIB: before 1yr of age
Yes. Have to do b/l central neck dissection. If nodes then modified radical lateral neck dissection as well
For pts with MEN2A what is the screening recommendations?
yes, annual ultrasound & calcitonin lvl starting at age 3 and thyroidectomy at age 5
When they give you a Cushing syndrome pt and asks for initial test but you don’t see low dose dexa suppression test, what two other tests?
24hr urine free cortisol excretion (>300 per day considered diagnostic for Cushing syndrome)
Late night salivary cortisol
After this, measure ACTH
What is radical parathyroidectomy and when do you do it?
What is the 5 and 10yr survival?
Parathyroid + ipsilateral thyroid lobectomy +/- ipsilateral modified radical node dissection depending on node involvement
For parathyroid carcinoma
5yr survival: 85%
10yr survival: 77%
What’s the difference between thyroid cancer stage I and stage II
what’s the age relevant to thyroid cancer staging?
Under 55
Stage I: any T / any N / M0
Stage II: any T / any N / M1
How is thyroid cancer staged for old people. What age is old?
> 55 is old for thyroid cancer
Stage III: T4 / any N / M0
Stage IVc: M1
What is the most common cause of Cushing syndrome overall?
What is the most common endogenous cause of Cushing syndrome?
Steroid use is most common
Most common endogenous is pituitary adenoma
Solid sheets of cells that do not contain colloid.
What thyroid lesion is this?
Follicular carcinoma
Hypercellularity and the presence of eosinophilic cells.
What thyroid lesion is this?
Hurthle cell carcinoma
Sheets of infiltrating neoplastic cells that are heterogenous in shape and size
What thyroid lesion is this?
Medullary thyroid cancer
What does anaplastic thyroid cancer look like on histology?
Spindle, giant multinucleated cells with occasional foci if differentiated cells
Intranuclear inclusions
What thyroid lesion?
Papillary thyroid cancer
When a pt presents with both Cushing and virilization you should suspect what?
Adrenocortical carcinoma
Gastrinoma tend to be malignant and require a formal resection and not just an enucleation. When is it appropriate to do enucleation for gastrinoma that’s in the head of the pancreas?
Single lesion <3 cm enucleation is appropriate
Follicular thyroid CA more common in men or women?
More common in women
T/F: hurthle cell cancer has a propensity to spread to cervical nodes
True. Even though follicular usually spreads hematomgeously, hurthle cell goes to the nodes
What is the most important predictor of survival for adrenal carcinoma with retroperitoneal node involvement?
what is the 5yr survival in the best case scenario?
Extent of resection. With adequate resection, almost 50% 5 yr survival
Question gives you a Cushing pt, asks for next step to make the diagnosis.
Low dose dexa vs 24hr urine free cortisol. Which one do you choose?
Urine cortisol first determines whether the pt has hypercortisolism or not
Low dose dexa tests whether the hypercortisolism is ACTH dependent or not
High dose dexa tests where the ACTH is coming from
What primary cancer is most likely to metastasizes to adrenal glands?
Lung
can’t find the right inferior parathyroid. you’re doing a bilateral neck exploration for 62yo with primary hyperpara with kidney stones.
what to do next?
if you don’t find it there then what to do next?
when to take out the ipsilateral thyroid?
ipsilateral cervical thymectomy because inferior parathyroid descends with thymus. the resected thymus should be sent for frozen
if not there, explore the carotid sheath from the clavicle to the bifurcation of the carotid artery.
or divide the middle thyroid vein to lift the thyroid and look in the tracheoesophageal space
ipsilateral thyroidectomy only if intrathyroid parathyroid on preoperative ultrasonography and if other ectopic locations have been ruled out
what is bethesda III on thyroid imaging and what to do next?
atypia of unknown significance
repeat FNA or lobectomy
1.5cm left papillary thyroid cancer, no suspicious nodes on US. patient wants unilateral lobectomy.
you did a unilateral lobectomy and you see a node just below the sternal notch. biopsy is (+) for PTC. what do you do next?
- is unilateral lobectomy still enough or do you need to do total?
- is central node dissection enough or do you need to do ipsilateral modified radial?
you need to do a total thyroidectomy because now with the node the patient is intermediate risk.
central dissection is enough. substernal still counts as central. preop US enough to r/o lateral nodes
you did a hemithyroidectomy for something benign. patient is in office 6 wks later. TSH is 8.5. completely asymptomatic. what do you do?
start levothyroxine
you did a total thyroid for medullary thyroid cancer. POD3, calcitonin level is 80pg/ml. what do you do?
assurance. can take months to normalize
parathyroid carcinoma. no evidence of nodal involvement on preop imaging. operation of choice?
en bloc resection. All structures that the tumor is invading are resected with gross negative margins. There has been no demonstrated benefit of completing an ipsilateral neck dissection without evidence of nodal disease
En bloc resection of the parathyroid gland and ipsilateral thyroid lobe along with regional lymph nodes is appropriate
how to distinguish between stage I vs. II adrenocortical carcinoma?
tumor size. whether the tumor is less than or greater than 5 cm
