Endocrine Flashcards
Bethesda classification 1
Non diagnostic - Repeat biopsy (4 weeks)
Bethesda classification 2
Benign - Repeat U/S in 12-24 months
Bethesda classification 3
Follicular cells of undetermined sig - Repeat FNAB
Bethesda classification 4
Follicular cells - lobectomy
Bethesda classification 5
Suspicious for malignancy - lobectomy or thyroidectomy
Bethesda classification 6
Malignant - thyroidectomy
Commonly injured area of RLN
At insertion of the cricothyroid membrane
Relationship of superior parathyroid to RLN
Posterior and lateral
Relationship of inferior parathyroid to RLN
Anterior and medial
common complication of total thyroidectomy
hypocalcemia in 10-20% patients, treated with calcium and vitamin D supplements. (dont forget thyroid replacement therapy)
Indications for post op radioiodine ablation
high risk (vascular invasion, etc) residual disease. metastatic disease. Positive lymph nodes. Follow thyroglobulin levels post op after total thyroidectomy.
Size of suspicious nodule needing biopsy, non suspicious nodule?
1 cm suspicious 1.5-2 cm non suspicious.
Indications for thyroid scitigraphy and information that can be learned
Patient with suppresed TSH and a thyroid nodule.
Can determine if patient has Grave’s disease and a potential cold, cancerous nodule, or if due to hot nodule (which is always benign)
Test needed pre op before thyroidectomy for thyroid malignancy
Ultrasound of central and lateral neck compartments.
Level 6 nodes for neck
hyoid bone superiorly
Brachiocephalic inferiorly
Carotid sheath laterally (peri thyroid nodes)
Level 1 nodes (neck)
Submental and submandibular gland. Above the hyoid, medially
Level 3/4 nodes neck
Along the jugular to the lateral border of the SCM
Level 5 nodes neck
lateral to the SCM
Indications for lobectomy in papillary thyroid cancer
< 1 cm mass (1-4 do total thyroidectomy)
If level 3 node is positive, subsequent LN dissection
Level 3 and 6 (always level 6 if doing neck dissection)
Percentage of patients with RLN paresis after thyroidectomy
10% (< 1% of permanent problems)
Used to support thyroid function after surgery prior to receiving radioiodine therapy
recombinant TSH (instead of synthroid)
Patient with new diagnosis of thyroid nodule and RET proto-oncogone gets what workup?
- Serum calcitonin
- Serum CEA
- Serum calcium
- serum PTH
- CT neck, chest, abdomen, and pelvis (triple phase) (calcitonin > 500)
- Bone scintigraphy (calcitonin > 500)
- serum metanephrines
Percent of medullary thyroid cancer that is familial
25% (most sporadic)
Age of prophylactic thyroidectomy for MEN2A? MEN2B
5 years old, 6 months
Indication for contralateral neck dissection in MTC
Calcitonin > 200
Superior aspect of level 2, 3, 4 anterior triangle dissection
Inferior edge of digastric and omohyoid muscles.
Treatment of post operative chyle leak after neck dissection
Fat free diet, compression. May need surgical exploration with ligation.
Post op follow up MTC
3, 6, 6, 1 year and annually with calcitonin
If elevated, < 150 - neck U/S
If elevated > 150, metastatic work up (neck, chest, triple phase abdomen/pelvis, bone scintigraphy)
Miami criteria for PTH normazliation
> 50% drop in PTH, normalization of PTH values.
Good regimen would be pre-anesthesia, pre-excision, 5, 10, 15 min post excision.
Non PTH mediated reasons for hypercalcemia
- PTHrP (malignancy)
- Granulomatous disease (sarcoid, TB)
- Adrenal insuff
- Vitamin toxicity
- Milk alkali
- Prolonged immobilization
- Lithium (actually PTH mediated)
Operation for parathyroid carcinoma
Parathyroidectomy and thyroid lobectomy
Familial hypercalcemic hypocalciuria
SHOULD NOT HAVE SURGERY
Get 24 hour urine calcium - if low, then have diagnosis. High in primary HPT.
Work up for patients with hypercalcemia
- Serum calcium, ionized calcium, PTH, BMP (for chloride and phosphate)
- 24 urine calcium
- DEXA scan for asymptomatic patients, looking for bone loss.
- Renal U/S looking for nephrolithiasis (or CT)
- Neck U/S
- Technetium Sestimibi with SPECT
Missing superior gland
- Retroesophageal space explored
- Carotid sheath opened and explored from bifurcation to base of neck
Missing Inferior gland
- Thymus
- Intrathyroidal parathyroid adenoma
All 4 glands discovered, but persistent PTH elevation.
Supernumary parathyroid glands (usually in the thymus) must do bilateral thymectomy.
Percentage of adrenal incedentalomas that are functional
20%
Adrenal protocol CT
- Non contrast CT
- Rapid injection of contrast with arterial phase 60s later
- 15 min delayed washout phase
Benign mass is < 10 HU on noncontrast scan and > 60% washout (lipid rich)
Biochemical evaluation of adrenal mass
- Serum potassium
- Serum aldosterone (possible need for venous sampling)
- Plasma renin activity
- Plasma and urine metanephrines/normetanephrines
- Fasting AM cortisol (potentially followed by 24 hour cortisol and suppression tests)
- ACTH
- DHEAS
Findings with functional aldosteronoma
- Hypokalemia
- Elevated plasma aldosterone
- Low renin activity
Preop treatment of pheochromocytoma
- Alpha blockade first (phenoxybenzamine - nonselective; doxazosin - selective) for 10-14 days pre procedure
- Beta blockade after a week of alpha blockade
Pre op treatment for patients with Cushing syndrome
Stress dose steroids secondary to suppression of other adrenal gland.
May need adrenolytic (ketoconazole or mitotane)
Pre op treatment for Conn’s syndrome
Spironolactone
Additional work up if concerned about ACC
- Chest CT
- ? bone scintigraphy (if symptoms)
- ? head CT (if symptoms)
MRI characteristic of pheo
Bright T2 (water H2O)
Adjuvant therapy for high risk, locally advanced ACC
Mitotane (2 years, many drug interactions, GI and neuro side effects) Usually with radiation.
Ki 67 index > 10%
Therapy for advanced ACC
EDP-M
- Etoposide
- Doxirubicin
- Cisplatin
- Mitotane
(Debulking is option if > 90% can be removed and good response to chemoradiation)
Most common causea of hypercortisolisms
- Exogenous steroids
- hypersecretion of ACTH from pituitary (Cushing’s disease)
- Adrenal hypercortisolisms from tumor or bilateral hyperplasia
- Ectopic ACTH producing tumors
Patient with elevated 24 hour urine cortisol and low ACTH
Adrenal source of cortisol
Patient with elevated 24 hour urine cortisol and elevated ACTH
Need to do DST (pituitary ACTH will be suppresed and AM cortisol will be lower. SCLC ACTH is not suppressed and cortisol will be high in AM).
Cl to PHos ratio suggestive of HPT
>33
Keys to right adrenalectomy
left lateral decubitus
mobilize the right lobe of liver by incising triangular ligament to level of hepatic vein.
? hepatic flexure
dissect vein draining into IVC
Harmonic dissection of vessels near capsule.
Keys to a left adrenalectomy
right lateral decubitus
mobilize the splenic flexure
Mobilze the spleen and distal pancreas
Divide inferior phrenic vein and vein draining into left renal vein
Harmonic dissection of adrenal close to capsule.
differential for hard to control HTN
- Conn’s syndrome
- Pheo
- Hypercortisolism
- Renal artery stenosis
- ESRD
- Hyperthyroidism
Essential part of work up for Conn’s syndrome, even in presence of imaging findings of nodule
Selective venous sampling due to possible presence of smaller functioning nodule.
(access adrenal vein, cosyntropin, then aldosterone/cortisol ratio - higher is more confirmatory)
Pheo 10% rule
- 10% malignant
- 10% extra-adrenal
- 10% bilateral
- 10% part of familial syndromes
Pheo familial syndromes (6)
- MEN2 (A, B)
- VHL
- NF1
- tuberous sclerosis
- Sturge-weber
- familial paraganglioma syndrome
Extraadreanal location of pheo
Along sympathetic chain, most common organ of ZUckercandl
High dose dexamethasone suppression test will suppress ACTH in…
Cushing disease (ACTH secreting pituitary tumor)
Does not suppress ectopic ACTH secreting tumor
somatostatinoma syndrome (and confirmatory somatostatin levels)
diabetes, hypochlorydia, gallstones (somatostatin > 100 pg/mL)
Calcium level diagnostic of parathyroid carcinoma
13
treatement is radical parathyroidectomy with ipsalateral thyroidectomy
Name of rash and associated condition
necrolytic migratory erythema
glucagonoma (also dermatitis, stomatitis, hyperglycemia). Located in distal pancreas
Marker of better prognosis when resecting isolated adrenal mets
length of time between primary cancer removal and adrenal met
Patients with von hippel lindau should be screend for…
renal cell cancer
CNS and retinal hemangioblastoma
pheochromocytoma
Histology key works for various thyroid cancers
papillary
follicular
anaplastic
medullary
papillary: large crowded nucleai, abundant cytoplasm, calcified laminated densities
follicular: solid sheets of cells without colloid
anaplastic: giant multinucleated
medullary: infiltrating neoplastic cells
Diagnostic criteria for insulinoma
neuroglycopenic symptoms resolved with glucose
fasting glucose < 45
serum insulin > 5 µU/L
elevated C peptide and proinsulin to r/o factitious insulin
Relative potencies of
Hydrocortisone
Prednisone
methylprednisolone
dexamethasone
Hydrocortison 1
Prednisone 4
solumedrol 5
dexamethasone 30
Normal levels of 24 hour cortosol
Diagnostic levels of Cushing Syndrome
< 90 mcg/24 hour
> 300 mcg/24 hours
Most common cause of Conn’s syndrome unilateral adenoma or bilateral adrenal hyperplasia
Bilateral adrenal hyperplasia
work up for adrenal insufficiency
Main concern with Reidel thyroiditis
Compressive symptoms; may need isthmusectomy since total thyroidectomy may not be possible. Chronic treatment with steroids, methotrexate, or tamoxifen
Most common cancer to metastasize to adrenals
lung cancer
The least important prognostic indicator for thyroid cancer (papillary and follicular) among
Age, size of tumor, lymph node involvement
lymph node involvement; minimal effect on survival
PTH effects on calcium and phos in the kidney
Prevents secretion of calcium in Distal convoluted tubules
Promotes secretion of phos in proximal convoluted tubules.
most common cause of endogenous cushing syndrome
ACTH secreting pituitary tumor
Treatment for unlocalized gastrinoma
vagotomy to decrease PPI requirement
Most common cause of hypercalcemia > 13
cancer, but most commonly breast or Multiple myeloma. Parathyroid cancer can also cause, but less likely.
Indications for unilateral thyroidectomy in patients with thyroid cancer
low risk features, size < 4 cm
Bilateral adrenal venous sampling should be considered for pateints older than…
35 year old.
location of functional PNETs in pancreas
Gastrinoma
insulinopma
Glucagonoma
VIPoma
Somatostatinoma
Gastrinoma: Gastrinoma triangle
Insulinoma: evenly throughout pancreas
Glucagonoma: Body and tail
VIPoma: Body and tail
Somatostatinoma: head of pancreas
