Endocrine Disorders

Question 1

Things to ask a patient in the H&P with a solitary asymptomatic thyroid nodule

Answer 1

Radiation hx (10-25 years ago, low-dose = 40% risk w/papillary being the most common), voice and airway sx and pattern of nodule growth.

Question 2

Next step in a patient with a painless solitary thyroid nodule and hx of neck radiation

Answer 2

Proceed directly to thyroidectomy if the nodule is hard, fixed and the patient has associated dyspnea, hoarseness or cervical LN enlargement. If it is less likely to be malignant do FNA.

Question 3

What type of thyroid cancer has a strong autosomal dominant inheritance pattern and is often seen in families? How can you screen for it?

Answer 3

Medullary thyroid carcinoma can be due to autosomal dominant mutation of the RET protoncogene and is involved in MEN2a (+ pheo + parathyroid) and MEN2b (+ marginoid w/mucosal neuromas + pheo). You can screen for this by looking for high levels of calcitonin.

Question 4

In addition to FNA, what other tests can be useful in working up a patient with suspected thyroid cancer.

Answer 4

Radioactive scan for hot vs. cold nodules, u/s to determine if cystic and TSH levels are all appropriate after getting path results from the FNA.

Question 5

Tx for a colloid nodule dx by thyroid FNA

Answer 5

Thyroid suppression only

Question 6

Tx for this dx by thyroid FNA

Answer 6

Note the orphan Annie nuclei indicating papillary thyroid carcinoma, they also sometimes have Psammoma bodies. This patient needs total thyroidectomy if > 1.5 cm or PHMx is + for neck radiation. Limited thyroid lobectomy and isthmusectomy can be done in patients with no hx of neck radiation. Both surgeries can have +/- berry picking LNs. Finish off w/thyroid hormone suppression +/- I-131 ablation

Question 7

Tx for this dx by thyroid FNA

Answer 7

Medullary thyroid carcinoma due to proliferation of C cells (parafollicular cells) is highly malignant and needs total thyroidectomy +/- central and lateral neck node dissection, +/- neck irradiation. Note the amyloid deposits that stain due to high production of calcitonin.

Question 8

Tx for this patient in his 7th decade with this dx on thyroid FNA

Answer 8

Anaplastic carcinoma has +LNs 50% of the time, distant mets 30% of the time (lung most common) and an extremely poor prognosis. Tx for anaplastic thyroid cancer is chemorads +/- surgical salvage operation w/wide excision

Question 9

Tx for this dx on thyroid FNA

Answer 9

Note the Hurthle cells, indicating possible Hashimoto thyroiditis or adenoma. Note that you cannot make a definitive dx of Hurthle cell or follicular carcinoma (shown below) on FNA and lobectomy is appropriate with total thyroidectomy if cancer is present. If thyroiditis, hormone replacement alone is fine.

Question 10

What are the risks of thyroidectomy?

Answer 10

Always bleeding/infection. Injury to unilateral recurrent laryngeal nerve = hoarsenss. Injury to bilateral recurrent laryngeal nerves = cord paralysis and tracheostomy. Injury to superior laryngeal nerve = loss of high pitch singing voice. Loss of parathyroids = hypocalcemia.

Question 11

A patient presents after biopsy of a thyroid nodule with the image below. How do you manage this patient?

Answer 11

Follicular cancer, which is more prevalent in I-deficient areas, can be treated with lobectomy and isthmusectomy. Total thyroidectomy is indicated if > 4cm. If frozen section shows clear dx of follicular cancer total thyroidectomy is warranted if > 1cm.

Question 12

Prognostic indicators for papillary cancer

Answer 12

“AGES”: age > 40, higher grade, extensive disease and large size are all poor indicators. 10 year survival in low risk pts is ~ 100%. In high risk patient ~20%.

Question 13

Post-op surveillance in a patient with thyroidectomy and LN dissection due to medullary thyroid cancer

Answer 13

Serum calcitonin and CEA can be useful markers for indicating recurrence. If the patient had LN involvement 10 year survival is 45%, so you really need to be on the lookout for these guys as opposed to those who had local disease with a 10 year survival of 80%.

Question 14

Lab indicators of primary hyperparathyroidism

Answer 14

Elevated PTH and elevated serum Ca

Question 15

What does this patient with hyperparathyroidism present with?

Answer 15

Osteitis fibrosa cystica

Question 16

Most common cause of primary hyperparathyroidism

Answer 16

Parathyroid adenomas followed by parathyroid hyperplasia. Parathyroid carcinoma is preset in < 2% of cases

Question 17

Common presenting sx of hyperparathyroidism

Answer 17

Muscle weakness, myalgia, arthralgia, nephrolithiasis, constipation, polyuria, psych disorders and PUD…i.e. painful bone, kidney stones, abdominal groans and psychiatric overtones.

Question 18

Surgical management of parathyroid adenomas

Answer 18

Find all 4, sample them to make sure the ones you leave in are normal and take out the adenoma. If you can’t find all 4, you need to close and order sestamibi scan, MRI, CIT, u/s, angiography or venous sampling to find the missing parathyroid. Once you find it, you can re-explore and take it out.

Question 19

What are common locations for ectopic parathyroid glands?

Answer 19

Most common location for a missing inferior gland is in the thymus due to migration with it from the 3rd pharyngeal pouch during embryogenesis. Tx w/thymectomy. Other common locations include intrathyroidal, in the tracheoesophageal greoove (especially ectopic supernumerary glands), carotid sheath and intravagal.

Question 20

Complications of parathyroidectomy

Answer 20

Same as thyroidectomy + risk of hypocalcemia (tetany, + Chvostek) and hyperphosphatemia if you remove all of the glands.

Question 21

When do most surgeons recommend parathyroid exploration for asymptomatic hypercalcemia?

Answer 21

Serum Ca > 11

Question 22

Where do the superior parathyroids come from?

Answer 22

4th pharyngeal pouch w/the thyroid gland

Question 23

Common causes of acute hypercalcemia

Answer 23

Parathyroid adenoma (increased PTH), metastatic breast carinoma (osteolytic), multiple myeloma (activates osteoclasts), hyperthyroidism (T3 increases bone resorption), sarcoidosis (macrophages make 1,25-OH-D3), milk alkali syndrome (increased ingestion of Ca-carbonate = alkalosis = decreased Ca renal excretion), vitamin A intoxication (increases bone resorption by IL-6), thiazides (Ca-sparing diuretic), renal cell carcinoma (PTHrP, IL-6, osteolysis), lung SCC (PTHrP) and familial hypocalciuric hypercalcemia (loss of Ca-sensing receptor in parathyroids and kidneys).

Question 24

Acute tx for hypercalcemia

Answer 24

Hypercalcemia causes osmotic diuresis, resulting in fluid depletion and increasing serum [Ca]. Tx initially w/IVFs, furosemide to increase Ca excretion, bisphosphonates and then go for the underlying cause. Long term you can use mithramycin, calcitonin and glucocorticoids to lower Ca levels.

Question 25

Why are patients with renal failure at risk for hyperparathyroidism?

Answer 25

Because they are the definition of secondary hyperparathyroidism. Chronic renal failure results in PO4 retention. Hyperphosphatemia impairs Ca absorption from the gut and vitamin D metabolism and causes hypocalcemia and elevated PTH levels.

Question 26

What are indications for surgery in patients with secondary hyperparathyroidism? How do you do the surgery?

Answer 26

Bone pain, fractures, intractable pruritus or ectopic calcifications of soft tissue are indications for excision of all parathyroid glands except 50mg of tissue that is placed in the arm.

Question 27

Why are renal transplant patients at risk for hyperparathyroidism? What are surgical indications for it?

Answer 27

They define tertiary hyperparathyroidism because the thyroids fail to respond to new kidneys that actually do their job and continue to overproduce PTH. If sx do not resolve after 1 year 3.5 gland resection is indicated.

Question 28

Medication to never administer in a patient with suspect pheo

Answer 28

Beta-blockers alone, this will result in unopposed alpha-receptor stimulation, vasoconstriction and fatal HTN

Question 29

Rule of 10s

Answer 29

Pheos are 10% malignant, 10% ectopic, 10% EPI producers and 10% bilateral

Question 30

Dx of pheo

Answer 30

Urinary cetechols, metanephrine and VMA. Get a T2 MRI to localize tumor, octreotide scan if MRI doesnt work and nuclear I-131 metaiodobenzylguanidine (MIBG) scan (selectively accumulates in chromaffin cells) as a last resort to find the damn thing.

Question 31

Pre-op preparation of a patient getting a pheo resected

Answer 31

Phenoxybenzamine 10-14 days prior to surgery for BP control. Add beta-blockade if tachycardia persists or pt has previous heart disease.

Question 32

What type of Ca do you give a patient who is coding and is hypocalcemic?

Answer 32

CaCl, it burns really bad when given, but has a higher ionized Ca level than Ca-gluconate

Question 33

Surgical approach for pheo resection

Answer 33

1st ligate all venous drainage before manipulation of the tumor to prevent catecholamine release systemically.

Question 34

A patient presents with sudden onset, swollen and tender thyroid gland. PE reveals a mass. What is the most likely dx? How do you tx?

Answer 34

de Quervain's thyroiditis. Patients present with hyperthyroidism early on due to sudden release of T4 from injured follicles. Confirm dx with biopsy looking for giant cell granulomas around degenerating thyroid follicles. Tx w/analgesics and aspirin +/- steroids.

Question 35

A patient presents with sudden onset, swollen and tender thyroid gland. PE reveals a mass. When is surgery appropriate for this patient?

Answer 35

If she has acute suppurative thyroiditis from strep, staph or pseudomonas. Other rare causes include aspergillosis, actinomycoses and syphilis. Tx w/abscess drainage + abs or antifungals

Question 36

A patient presents with sudden onset, swollen and non-tender thyroid gland. PE reveals a mass. Biopsy is shown below. How do you tx this patient?

Answer 36

This is Hashimoto's thyroidits (chronic lymphocytic thyroiditis). Confirm w/labs looking for low T3 and T4 w/normal TSH due to autoimmune destruction of thyroid tissue. There is no tx but you should biopsy it to r/o papillary carcinoma and thyroid lymphomas. Only resect if compressing trachea.

Question 37

MEN1

Answer 37

Pituitary adenoma, parathyroid hyperplasia and pancreatic endocrine tumors (gastrinoma, insulinoma, VIPoma)

Question 38

A patient presents with intractable duodenal ulcers. You get a serum gastrin level and it is elevated at 1200. Where do you go from here?

Answer 38

Hypergastrinemia can be due to gastrinoma, incomplete previous gastric resection or G-cell hyperplasia. You should get CT or MRI to localize a tumor in the pancreas if present. If pancreatic gastrinoma is present, solitary and not from MEN1, then resection is appropriate. If multiple and associated with MEN1 surgery is controversial. Surgical enucleation and preservation of pancreatic mass is preserved, however, if the mass abuts a large pancreatic duct distal pancreatectomy or Whipply should be performed. If the tumor is non-resectable, gastric resection or highly selective vagotomy are appropriate with chemotherapy.

Question 39

Where is the gastrinoma triangle?

Answer 39

This is where the majority of gastrinomas are found.

Question 40

A patient presents with dizziness and diaphoresis with altered mental status. Labs reveal elevated C-peptide and serum glc \< 60 and symptoms go away with glc administration. CT shows a mass in the head of the pancreas. How do you manage this patient of the tumor is unresectable?

Answer 40

He presents with the Whipple triad: fasting hypoglycemia glc \< 60, symptomatic hypoglycemia and relief w/glc administration indicating and insulinoma. If surgical resection by enucleation or Whipple procedure is not warranted, you can give diazoxide to inhibit insulin release and manage sx.

Question 41

MEN2a

Answer 41

Medullary thyroid cancer, parathyroid hyperplasia and pheochromocytoma (more likely to be bilateral when associated with MEN)

Question 42

MEN2b

Answer 42

Medullary thyroid cancer, Marfinoid habitus and ganglioneuromas

Question 43

When is surgery recommended for an adrenal incidentaloma

Answer 43

\> 4cm has increased risk of adrenal cortical carcinoma and should be resected, functional masses (increased catecholamines, cortisol or decreased K+) should also be resected. You should also consider lung cancer because the adrenal glands are common metastatic sites.