Endocrine Surgery Flashcards
When does calcitonin reach its nadir after thyroidectomy
several months later
which medications cause an increase in hepatic metabolism of thyroid hormone?
anti-epileptics (e.g. phenobarbital, carbamazepine, and phenytoin)
Patient with hyperparathyroidism and thyroid nodule consistent with medullary thyroid carcinoma, what should you think about?
MEN2A
- check metanephrines prior to surgery
patient s/p 3 1/2 parathyroidectomy, obs overnight. Perioral numbness and finger tip numbness refractory to oral calcium…next step
IV calcium gluconate, BMP draw
Initial treatment for hypercalcemia secondary to hyperparathyroidism
- fluid resuscitation
- then after they are resuscitated loop diuretic and sestamibi scan
First test to order in any patient after some kind of thyroid resection if they have symptoms
TSH
indication for surgical treatment of hyperparathyroidism
- Ca concentration 1.0 or above
- T-score of -2.5 or less
- Vertebral fracture
- Creatinine clearance < 60 mL/min
- 24 urinary calcium > 400 mg/d
- presence of nephrolithiasis
- age < 50
parathyroid taken for histology shows single focus of chief cells, surrounded by a compressed rim of normal tissue
parathyroid adenoma
parathyroid taken for histology shows diffuse proliferation of clear cells with little remaining normal tissue
parathyroid hyperplasia
parathyroid taken for histology shows marked mitotic activity, dense fibrous stroma, and evidence of local invasion into the capsule or surrounding vessels
parathyroid malignancy
parathyroid taken for histology shows the presence of C cell hyperplasia and dispersed plasmacytoid cells
medullary thyroid carcinoma
You got a lymph node not a parathyroid gland
female with strong family history of thyroid cancer, genetic testing shows gain of function in RET protocol-oncogene. what type of cancer is she predisposed to?
Medullary thyroid cancer
Patient with hyperthyroidism, with diffuse uptake on imaging (no hot or cold nodules). What is the first step in treatment?
initiation of anti-thyroid medication and beta-blockade
must be euthyroid before any definitive management
risk of malignancy in patients younger than 14 if they have a thyroid nodule
50%
Miami Criterion for intraoperative PTH monitoring
50% drop in PTH at 10 minutes post excision, if not met then redraw PTH at 20 minutes post excision. If still above the 50% threshold at 20 minutes then explore other parathyroid glands
What do you use the Secretin Stimulation test for?
- presence of gastrinoma
How do you test for the presence of a gastrinoma?
- Secretin stimulation test
- considered positive if gastrin level > 120 pg/mL
Adrenal mass that measures 4.1 cm and has loss of signal on opposed-phase chemical shifting imaging (MRI). What is this mass most likely
Adrenal Adenoma
Which anti-thyroid medication is used during the first trimester?
Propylthiouracil (PTU)
Which anti-thyroid medication is used after the start of the second trimester?
Methimazole (MMI)
Which anti-thyroid medication is preferred if there are no contraindications
Methimazole (MMI)
Better side effect profile
net effect of parathyroid hormone release
elevation of serum calcium levels
scan used to assess pheochromocytomas
FDG F-DOPA
best treatment for recurrent parathyroid cancer?
repeat surgery
Features on US that would suggest thyroid malignancy
- taller than wide
- solid component
- hypo-echoic echogenicity
- irregular borders
- hyper-vascular
you find parathyroid tissue invading adjacent structures when exploring for a presumed parathyroid adenoma, what is this?
Parathyroid malignancy
what kind of resection is standard for a parathyroid malignancy
- enbloc resection of parathyroid mass and any adjacent tissue (ipsilateral thyroid lobe and isthmus)
- central lymph node dissection
what lab value do you use to track recurrence of thyroid carcinoma?
thyroglobulin
what is the next step after identification of a pheochromocytoma
Alpha blockade
describe post-operative subclinical hypothyroidism after a thyroid lobectomy
- asx patient
- elevated TSH
- low or normal free thyroxine (T4)
what test can you use that is specific for graves disease
Thyroid-Stimulating hormone receptor Antibodies (TRAb)
first line anti-hypertensive intra-op for a pheochromocytoma
Nitroprusside
what does Bethesda III correspond to
atypia of undetermined significance, for a thyroid nodule
- repeat FNA or lobectomy
patient with goiter and elevated anti-thyroid peroxidase antibodies, what do they have
Hashimoto Thyroiditis
when performing a 4-gland exploration in the setting of MEN1 for hyperparathyroidism, what else needs to be included to ensure all hyperactive parathyroid tissue is removed
Thymectomy
major landmarks to identify during thyroidectomy to avoid injuring recurrent laryngeal nerve
- superior parathyroid
- tubercle of Zuckerkandl
- ligament of berry
- tracheoesophageal groove
- crossing of inferior thyroid artery
most common location to injure recurrent laryngeal nerve during thyroidectomy
ligament of berry (where thyroid attaches to tracheal rings)
what is a normal value for TSH
.05-5.0 mlU/L
which IV steroid is short-acting
Hydrocortisone
which IV steroid is long-acting
Methylprednisone
what is a “stress dose” of hydrocortisone in a patient with adrenal crisis
100 mg IV
how do you treat a trauma patient with suspected HPA suppression
- 100 mg IV bolus of hydrocortisone
- followed by 200 mg/24hr of hydrocortisone (continuous or in bolus 50mg/6hr)
Mnemonic for adrenal gland hormone production by location within the gland
GFR
salt, sugar sex
- aldosterone - Zona glomerulosa
- glucocorticoids - Zona fasciculata
- sex steroids - Zona reticulosa
in what part of the adrenal gland are mineralocorticoids made
Zona glomerulosa
in what part of the adrenal gland are glucocorticoids made
Zona fasciculata
in what part of the adrenal gland are sex steroids made
Zona reticulosa
what kind of parathyroid surgery do you perform in MEN1
excision of 3.5 glands to prevent recurrent hyperparathyroidism
- aldosterone is made in what part of the adrenal gland
Zona glomerulosa
- glucocorticoids is made in what part of the adrenal gland
- Zona fasciculata
- sex steroids are made in what part of the adrenal gland
- Zona reticulosa
Patient with MEN1, what kind of parathyroid resection do you need
3.5 glands removed
how do you determine the dose of glucocorticoid replacement in a patient
12 mg/m^2
where are superior parathyroid glands typically located?
posteromedial surface of middle/superior thyroid. posterior to recurrent laryngeal nerve
where is the most common location for an ectopic superior parathyroid gland
tracheo-esophageal groove
what compartments are included a lateral neck dissection
II, III, IV, and V
What landmarks in the neck, in the longitudinal plane separate compartments?
Hyoid bone and cricoid cartilage
what landmarks in the neck, in the horizontal plane, separate compartments
Midline, carotid artery, and lateral edge of sternocleidomastoid
tumor marker for papillary thyroid cancer
Thyroglobulin
Tumor Marker for medullary thyroid cancer
Calcitonin
Most common atypical location for pheochromocytoma?
Peri-aortic fat at that bifurcation of aorta
What is the collection of chromaffin cells within the peri-aortic fat at the bifurcation of the aorta called, and what is the significance?
Organ of Zuckerandl
- atypical location of pheochromocytoma
Psammoma bodies on FNA of a thyroid nodule…pathognomonic for?
thyroid cancer
Classic cytologic features of papillary thyroid cancer?
overlapping nuclei
intranuclear grooves
what must you do whenever you encounter a patient with an adrenal mass
measure 24-hour urine catecholamines and metabolites
- need to rule out pheochromocytoma
most common locations for ectopic inferior glands, during parathyroidectomy
- thymus
- thyroid lobe, after division of middle thyroid vein to allow more mobilization
- last step is hemi-thyroidectomy
What is the role of glucocorticoids in thyroid storm
decrease the peripheral conversion of T4 to T3
