ENDOCRINE Flashcards
Painful thyroid + thyrotoxicosis
subacute granulomatous thyroiditis
Phases of subacute granulomatous thyroiditis
Initial hyperthyroid (similar to influenza) and low uptake on RAI uptake scans.
RAI uptake with Graves disease
Increased
RAI uptake with postpartum thyroiditis
Hyperthyroid phase
Decreased RAI uptake
Riedel thyroiditis
Rare chronic inflamm disease of thyroid that causes fibrosis of thyroid –> hard, nontender thyroid
Antibodies assoc with Graves disase
Thyroid stimulating hormone receptor antibodies
1.8 cm thyroid nodule –> FNA shows follicular lesion. Next stop?
Diagnostic lobectomy and/or molecular testing
Central neck LN
Level VI
Lateral neck LN
Level II-V
Primary hyperPTH + medullary thyroid CA should raise suspicion for?
MEN 2A - look for pheo!
For pts with highest risk mutation RET proto-oncogene (Men IIB) when should thyroidectomy be performed?
Before age 1 or at time of dx. Also check calcitonin, US and r/o pheo.
Bacteria in suppurative thyroiditis
Staph aureus or strep pyo
Calcitonin levels after thyroidectomy in MEN 2A
Slowly decrease and may not reach nadir for several months
Follicular neoplasm on FNA
Thyroid lobectomy
Rapidly growing thyroid mass with FNA showing large irregular lymphoid cells
Thyroid lymphoma - give chemoXRT (CHOP).
Bethesda III - next step?
Repeat FNA or lobectomy atypica of undetermined significance or FLUS
Signs that lymph node is mets
Malignant LN may demonstrate increased size, round shape, loss of central fatty hilum/thinning of hilum, peripheral or mixed vascualrity, presence of microcalcifications, or ill-defined margins
Tumor marker for PTC
Thyroglobulin
Preoperative SSKI/Lugol iodine before thyroidectomy reduces?
Intraoperative blood loss (decreases vascularity of thyroid gland)
Level III LN location
Middle internal jug chain
Inferior margin of hyoid to inferior margin of cricoid, anterior to posterior border of SCM, lateral to medial margin of common carotid a
Which medications can increase hepatic metabolism of thyroid hormone?
Antiepileptics (including phenobarb, carbamazepine and phenytoin). Pts on these meds often require higher than normal doses of thyroxine
In Men 2a, what surgery comes first?
Adrenalectomy
What size nodules do not require routine sonographic follow up
If purely cystic/low suspicion on US and <1 cm
ANtibodies assoc with Hashimoto thyroiditis
Antithyroid peroxidase antibodies
Child under 14 with thyroid nodule
Nearly 50% chance of malignancy
Increased risk of hypothyroidism after hemithyroidectomy
Preoperate Hashimoto dz (anti TPO antibodies)
How does follicular thyroid CA spread?
Hematogeneously
What size MTC warrants a CLND?
> 1 cm
Also: clinically positive LN, bilobe disease
Where do parafollicular cells derive from?
4th pharyngeal pouch
Large crowded nuclei with folded and grooved margins, intranuclear cytoplasmic inclusions
Papillary thyroid CA
Solid sheets of cells that do not contain colloid
Follicular CA
Hypercellularity and presence of eosinophilic cells
Hurthle cell CA
Sheets of infiltrating neoplastic cells heterogenous in shape and size
Medullary thyroid CA
Spindle, polygonal, giant multinucleated cells with occasional foci of undifferentiated cells
Anaplastic thyroid CA
Tx of subacute thyroiditis
NSAIDs or steroids
Child with MEN2A - when thyroidectomy?
Before age of 5 should have total with CLND
Men 2B
Medullary thyroid CA + Marfans + pheo + mucosal neuromas
MEN 2A
Medullary thyroid CA + primary hyperPTH + pheo
First mx of MEN 2A/B
MTC
What adrenal location produces most cortisol?
Zona fasciculata (glucocorticoids)
Pt with MEN1 dx with parathyroid adenoma. What is operative plan?
Bilateral cervical exploration with resection of 3 and 1/2 glands as well as bilateral thymectomy (higher propensity for ectopic as well as thymic tumors)
Pathogenesis of FHH as well as diagnosis
Inactivating mutations in the calcium-sensing receptor in the parathyroid glands and the kidneys –> high serum ca
-reduction in urinary Ca excretion
What is the CCCR ratio and what is the diagnostic value in FHH?
24 hr urinary creatinine excretion and serum calcium and creatinine concentrations
If <0.01 (in a vitamin D replete individual) diagnostic of FHH
Elevated serum cortisol and low ACTH
Adrenal adenoma (ACTH independent Cushing syndrome)
Secondary hyperPTH
Secondary hyperparathyroidism occurs due to chronic renal failure. Phosphate retention and hyperphosphatemia leads to the decrease in serum calcium levels. This effect is aggravated by the reduction in 1-hydroxylase activity in the kidney which is necessary for the activation of vitamin D3. The secondary increase in PTH levels to compensate for the hypocalcemic effects is exacerbated by aluminum accumulation in bone.
Central neck dissection: Borders
Superior: horizontal line at the inferior border of the cricoid and RLN insertion point
Inferior: plane on level with the innominate artery
Lateral: Common carotid artery
Medial: Medial edge of contralateral strap muscles
Central neck dissection: level VI borders
defined superiorly by the hyoid bone, inferiorly by the sternal notch, laterally by the medial aspect of the carotid sheath, posteriorly by the prevertebral fascia, and anteriorly by the superficial layer of the deep cervical fascia.
Central neck dissection: level VII borders
Level VII lymph nodes are those associated with the brachiocephalic vein and innominate artery. The inferior boundary of level VII, included as the lowest portion of the ATA-defined CND, is defined by the innominate artery on the right (at its point of tracheal crossing) and the corresponding axial plane on the left.
Mgmt of recurrent parathyroid CA
re-exploration and resection. little value in chemo or XRT as its pretty radioresistant
First line for intraoperative HTN in pheo
Nitroprusside
Where do the inferior PTH glands arise from?
3rd branchial pouch
Basal fasting gastrin levels indicative of gastrinoma
An increase in gastrin levels of more than 120 pg/mL over basal fasting levels is positive. Serum gastrin levels usually peak by 10 minutes.
Dfif between stage I and II ACC
Size - tumor > or < 5 cm
After hypercortisolism has been diagnosed by a low-dose dexamethasone suppression test and/or a 24-hour urine cortisol collection, an adrenocorticotropic hormone (ACTH) level should be obtained. If the ACTH value is low (< 10 pg/mL)?
Adrenal lesion should be suspected
Discharge plan after aldosteronoma resection
All antihypertensive medications should be withheld unless it is necessary to wean patients off them. Carvedilol requires weaning to avoid rebound hypertension. A high-salt diet can help blunt the rebound hyperkalemia that occurs due to reversal of chronic suppression of the renin-angiotensin-aldosterone axis. Patients should return in 1 week for blood pressure monitoring and a chemistry panel to evaluate potassium levels.
How to test for dx of insulinoma
72 hour fast
Blood tested for serum glucose and immunoreactive insulin concentration every 6 hours and when symptoms develop. If develops neuroglycopenic sx the nserum levels of glucose, insulin, C-peptide and proinsulin are drawn and the fast is terminated. Dx made if develops neruoglycopenci symmptoms, serum glucose <45 mg/dL, concomitant serum level of insulin higher than 5 microU/L. Elevated levels of C-peptide (>0.7) and proinsulin are confirmatory and exclude factitious hypoglycemia
Where are insulinomas found in the pancreas?
Evenly distributed throughout
Arterial supply of adrenal gland
Superior adrenal a from inferior phrenic, middle adrenal from aorta, and inferior adrenal a from renal a
Where does the left adrenal vein drain into
Left renal vein after joining with left inferior phrenic vein
Dx of Conn syndrome
Due to lack of autoregulation by renin, a plasma aldosterone-to-renin ratio >25-30 (make sure you discontinue ACE inhibitors, diuretics, and beta adrenergic blockers)
Mechanism of aldosterone
Increases sodium retention in exchange for hydrogen in the cortical collecting tubules and potassium in the gut, salivary and sweat glands. Therefore in hyperaldosteronism pts have low serum K, high urinary K, low urinary Na and metabolic alkalosis
Sx of prolactinoma
Menstrual cycle dysfunction (amenorrhea), decreased bone density and osteopenia, galactorrhea, decreased libido, infertility, ED, and impaired vision.
Vision impairment in pituitary prolactinoma
Bitemporal hemianopsia
Possible gene mutation seen in some cases of ACC
somatic mutations in p53 (Li Fraumeni)
ectopic inferior parathyroid
thymus or thyroid. Undescended glands may be located anywhere within carotid sheath. Can also be located intra-thyroidally with greater frequency than superior glands
ectopic superior parathyroid
tracheoesophageal groove and retroesophageal region. May be intrathyroidal or, if undescended, located at piriform sinus
Cortisol elevated and ACTH is low
Cortisol secreting lesion (adrenal adenoma or adrenal hyperplasia)
RET oncogene
protooncogene that encodes a receptor tyrosine kinase protein. Mutations are inherited in an AD fashion.
Next step if pt with biochemical evidence of primary hyperaldosteronism and CT scan showing either no abnormalities or bilateral abnormalities
Bilateral adrenal venous sampling
What are sx of VIPoma
WDHA syndrome - watery diarrhea, hypokalemia, achlorhydria or acidosis
How to confirm dx of VIPoma
elevated fasting serum VIP level
First step in left adrenalectomy
Mobilization of splenic flexure of colon from left retroperitoneum
Diabetes, gallstones and steatorrhea
Somastinoma
Resection is indicated for all adrenal incidentalomas if they are?
functioning
First step in right adrenalectomy
Dividing right triangular ligament to mobilize right lobe of the liver
First line for bilateral adrenocortical hyperplasia
Spironolactone
Location of most somatostatinomas
Head or periampullary region
Which endocrine pancreatic tumors located in distal pancreas?
VIPoma, glucagonoma
MC cancer that spreads to adrenal
Lung. Then GI tract, breast, kidney, pancreas and skin
Confirmatory of somatostatinoma
Fasting plasma somatostatin leves >100 pg/mL
Most impt predictor of survival in ACC
adequacy of resecction
Dx of glucagonoma
Fasting glucagon >1000 mg/mL
Mixed presentation of Cushing syndrome and virilization should make you suspicious for
Adrenocortical carcinomma
postnatal congenital adrenal hyperplasia due to 21 hydroxylase enzyme deficiency
virilization, hirsutism polycystic ovaries irreg menses HYPOcortisolism HYPOaldosteronism
PTH increaess calcium by what 3 mechanisms
1) stim of Ca reabsorption in distal convoluted tubule
2) stimulation of osteoclasts and release of Ca from bone mineral stores
3) stimulation of formation of calcitriol (vit D) which incrases dietary absorption of calcium
MCC hyperaldosteronism
Bilatera ladrenal hyperplasia
Where do inferior parathyroid glands lie in association with RLN?
Anterior
*superior parathyroid glands lie posterior to RLN
Superior laryngeal nerve lcoation and function
Near superior pole of thyroid near trunk of superior thyroid a. Injury causes subtle voice changes and voice projection compromise
Cricothyroid muscle innervation
External branch of the superior laryngeal nerve
Blood supply of parathyroids
Inferior thyroid artery which is a branch of the thyrocervical trunk from the subclavian artery
Where are the superior parathyroid glands usually found in relatioon to the inferior thyroid arteries?
1-2 cm superior to inferior thyroid arteries
First endocrine mx in MEN1
hyperPTH
first endocrine mx in MEN2A
MTC
von Hippel Lindau characteristic tumors
CNS and retinal hemangioblastomas, clear cell RCC, pheo, pancreatic cystadenomas and neuroendocrine tumors, endolymphatic sac tumors and papillary cystatednomas of epididymis and broad ligament
Surveillance for VHL disease
- screen for signs of neuro sx, nystagmus, strabismus and white pupil
- age 1-4 years: eye/retinal exam using indirect ophthalmoscope
- 5-15 yrs: audiology assessment every 2-3 years
- 16+ quality US of abdomen and MRI +/- contrast every other year
- age 16: MRI of nervous system every 2-3 years and audiology exam by audiologist
- annual test for fractionated metanephrines (especially NE) using blood or urine test starting at 5 years old
If suspicious for ZES but gastrin level between 150-1000
Most sensitive test is secretin stimulated gastrin level. Positive test will show increase in gastrin of >200 pg/mL
What else causes increasd gastrin?
PPI use
H.pylori
Renal failure
Relative potency of hydrocortisone
1
Relative potency of prednisone
4
Relative potency of methylprednisone
5
Relative potency of dexamethasone
30
What if you cannot localize a gastrinoma despite all efforts?
Highly selective vagotomy
Most important determinant of survival in pts that undergo resection of adrenal met
Disease free interval between initial CA and mets (>6 months)
Total parathyroidectomy more commonly performed in which MEN syndrome
MEN1
Selective parathyroidectomy of abnormal glands is more often oeperformed in pts with MEN2
Conn syndrome is most commonly caused by
bilateral adrenal hyperplasia
FEV1 of how much from contralateral lung required to proceed with pneumonectomy
800mL
tx of unlocalized gastrinoma despite all efforts
highly selective vagotomy
small <3 cm, sporadic pancreatic head gastrinomas - tx?
enucleation + regional LN dissection
5 infections that require negative pressure room isolation
measles COVID varicella tuberculosis SARS
single most impt RF for development of heart disease in US
Coronary heart disease
> 10 mg daily prednisone and minor procedure
25 mg of hydrocortisone at induction
> 10 mg daily prednisone dose in last 3 months and moderate surgery (hemicolectomy, open chole, hysterectomy)
usual preop steroids + 25 mg hydrocortisone at induction + 100 mg hydrocortisone/day for 24 hours
> 10 mg daily predinosone and major surgery
usual preop steroids + 25 mg hydrocortisone at induction + 100 mg hydrocortisone/day for 2-3 days
resume normal PO tx when GI function returned
TEF and anastomotic leak
most heal spontaneously
if you see a leak or suspect one, leave retropleural chest tube in place, keep NPO and abx may be administered
anti arrhythmic that can cause hypothyroidism
amiodarone
how soon are effects seen after calcitonin administration
6 hours
how does cinacalcet correct hypercalcemia
decreases production of PTH
what is mitotane used for
adrenal-lytic
residual, recurrent or metastatic ACC
what is metyrapone used for
adrenal hyperplasia - it blocks cortisol synthesis
what is metyrosine used for
inhibits tyrosine hydroxyalse causing decreased synthesis of catecholamines
given pre op in adrenalectomy (pheo) or in case of unresectable disease
simultaneous tumors in MEN 1 - what do you treat first?
hyperparathyroidism (4 gland resection with autotransplantation plus bilateral thymectomy)
Pheochromocytoma in MEN 2 - unilateral or bilateral? benign or malignant?
often bilateral
nearly always benign
Likelihood of malignancy when thyroid lights up on PET CT
21%
Long term vitamin D deficiency leads to
secondary hyperPTH
