Thyroid

Question 1

When performing a thyroidectomy, which of the following anatomic considerations is incorrect:

A. The middle thyroid veins drain into the internal jugular vein
B. The inferior thyroid artery arises directly from the external carotid artery.
C. The thyroidea ima artery arises directly from the aorta in 1% 4% of patients.
D. The ligament of Berry is located near the entry point of the recurrent laryngeal nerve (RLN).
E. Venous drainage of the thyroid gland is via the superior, middle, and inferior branches.

Answer 1

Answer : B

Question 2

2. A 45-year-old woman has chronic neck pain and a newly diagnosed posterior pharyngeal neck mass found on magnetic resonance imaging (MRI) (see image of transoral examination
   Fig. 16.1). The next best step in the appropriate management of this patient is:
   A. Computed tomography (CT)
   B. Cervical ultrasound
   C. Physical examination with observed swallowing
   D. Radioiodine uptake scan
   E. Observation

Answer 2

Answer : C

Question 3

3. A 46-year-old male is undergoing an anterior cervical disk fusion. Which of the following is correct with regard to the RLN?
   A. The left RLN loops around the subclavian artery and ascends medially into the neck.
   B. The right RLN loops around the inferior thyroid artery, ascends laterally to medially, and enters the cricothyroid membrane.
   C. The right inferior laryngeal nerve is nonrecurrent in 0.5%-1% of patients.
   D. The RLNs innervate the true vocal cords and the cricothyroid muscles.
   E. The medial branch of the RLN is primarily sensory.

Answer 3

Answer : C

Question 4

With regard to thyroid hormone synthesis and uptake, which of the following is correct?
A. lodine trapping involves endocytosis of circulating iodine particles.
B. In the euthyroid state, Triiodothyronine (T;) is the main hormone produced by the thyroid.
C. Thyroid peroxidase is responsible for the peripheral conversion of T, to thyroxine (T,).
D. Thyroglobulin is a glycoprotein synthesized in the rough endoplasmic reticulum of the thyrocyte.
E. The primary site of peripheral deiodination of T, to the active form T, occurs in the adrenal gland.

Answer 4

Answer : D

Question 5

Hypothyroidism can be associated with all of the following pharmacologic therapies except:
A. Lithium
B. Amiodarone
C. Interleukin-2
D. Propylthiouracil (PTU)
E. Cimetidine

Answer 5

Answer : E

Question 6

With regard to the pharmacologic treatment of hyperthyroid-ism, which of the following is incorrect?
A. PTU works by inhibiting organic binding of iodine and coupling of iodotyrosines.
B. PTU is associated with agranulocytosis.
C. PTU is the preferred treatment in pregnant patients.
D. Methimazole can worsen exophthalmos in patients with Graves’ disease.
E. Methimazole has a longer half-life and only requires once-daily dosing.

Answer 6

Answer : D

Question 7

All of the following are extrathyroidal manifestations of
Graves’ disease except:
A. Vitiligo
B. Pretibial myxedema
C. Exophthalmos
D. Myxedema coma
E. Acropachy

Answer 7

Answer : D

Question 8

Which of the following antibodies is diagnostic of patients with Graves’ disease?
A. Thyroglobulin antibodies (anti-Tg)
B. Thyroid peroxidase antibodies (anti-TPO)
C. Anticardiolipin antibodies
D. Thyroid-stimulating antibodies (anti-TSH)
E. Antimicrosomal antibodies

Answer 8

Answer : D

Question 9

A 42-year-old woman complains to her physician of symptoms associated with hyperthyroidism. On examination she has a palpable nodule, but no evidence of exophthalmos.
She does have pretibial myxedema. Her laboratory workup reveals a suppressed thyroid stimulating hormone (TSH) level with elevated free T,. What is the next best step in the management of this patient?
A. Radioactive 123 I uptake scan
B. Thyroid peroxidase antibodies (anti-TPO)
C. PTU
D. Fine-needle aspiration (FNA)
E. Cervical ultrasound

Answer 9

Answer : A

Question 10

Which of the following is not an acceptable indication for surgical treatment of hyperthyroidism of the patient in Question 9?
A. A nodule confirmed or suspicious for malignancy
B. Pretibial myxedema
C. Noncompliance with medical management
D. Age younger than 15 years
E. Severe Graves’ ophthalmopathy

Answer 10

Answer : B

Question 11

With regard to Hashimoto’s thyroiditis, which of the following is correct?
A. The majority of patients are transiently hypothyroid but with time return to a euthyroid state.
B. It is primarily treated surgically.
C. Radioactive iodine is useful in the treatment of Hashi-moto’s thyroiditis.
D. Thyroid microsomal antibodies are detected in the serum of patients.
E. Hashimoto’s thyroiditis is more common in men than in women.

Answer 11

Answer : D

Question 12

All of the following statements regarding Hürthle cell carcinoma are correct except:
A. It represents a subtype of papillary thyroid carcinoma.
B. It is associated with a higher mortality rate.
C. It is more likely to be multifocal compared with follicular
D. It demonstrates poor radioactive iodine uptake.
E. It is more likely than follicular carcinoma to have lymph node metastases.

Answer 12

Answer : A

Question 13

A patient is undergoing a planned total thyroidectomy for bilateral thyroid nodules, of which the right nodule was consistent with a follicular neoplasm with Hürthle cell features on FNA. During initial mobilization of the gland on the right side, the right RN was unintentionally transected.
What is the best next step in the management of this patient?
A. Repair RLN primarily.
B. Perform a frozen section of the contralateral nodule and proceed with total thyroidectomy only if the biopsy specimen suggests malignancy.
C. Perform right lobectomy and isthmusectomy.
D. Perform left subtotal lobectomy.
E. Perform right lobectomy with nodulectomy of the lesion located on the left.

Answer 13

Answer : C

Question 14

With regard to the pathologic features of thyroid carcinoma which of the following is correct?
A. Psammoma bodies are a feature of medullary thyroid carcinoma (MTC).
B. Hürthle cell carcinoma represents a subtype of anaplastic thyroid carcinoma.
C. Amyloid deposits are a characteristic of papillary thyroid carcinoma.
D. MTC typically spreads hematogenously.
E. Nuclear grooves and inclusions are a characteristic feature of papillary thyroid carcinoma.

Answer 14

Answer : E

Question 15

With regard to the pathologic features of thyroid carcinoma which of the following is correct?
A. Psammoma bodies are a feature of medullary thyroid carcinoma (MTC).
B. Hürthle cell carcinoma represents a subtype of anaplastic thyroid carcinoma.
C. Amyloid deposits are a characteristic of papillary thyroid carcinoma.
D. MTC typically spreads hematogenously.
E. Nuclear grooves and inclusions are a characteristic feature of papillary thyroid carcinoma.

Answer 15

Answer : E

Question 16

A 72-year-old woman with Hashimoto’s thyroiditis is evaluated for a rapidly enlarging neck mass. The patient takes levothyroxine replacement. Despite no change in her medication dosage, she has been experiencing fevers, night sweats, and weight loss. Ultrasound reveals a 4-cm left thyroid mass with a pseudocystic pattern. FNA is nondiag-nostic. What is the next step in the management of this patient?
A. Nonsteroidal antiinflammatory drugs
B. Repeated FNA
C. Radioactive iodine
D. Open or core biopsy
E. Increased dose of levothyroxine with follow-up ultra-
sound in 6 months

Answer 16

Answer : D

Question 17

Which of the following genes has been associated with a less favorable prognosis in patients with papillary thyroid carcinoma?
A. RET protooncogene
B. Ras
C. BRAF
D. Menin
E. p53

Answer 17

Answer : C

Question 18

An 82-year-old female with a long-standing history of a neck mass presents because of sudden rapid painful neck enlargement associated with a change in her voice and dysphagia.
NA biopsy reveals giant and multinucleated cells. All of the following are appropriate steps in the management of this patient except:
A. Immediate tracheostomy
B. Total thyroidectomy with LN dissection for intrathyroidal
C. Cytotoxic chemotherapy
D. Adjuvant radiation if performance status permits
E. En bloc resection for tumors with extrathyroidal
extension

Answer 18

Answer : A

Question 19

With regard to thyroid metastases, which of the following malignancies most commonly spreads to the thyroid?
A. Renal cell carcinoma
B. Breast cancer
C. Colon cancer
D. Lung cancer
E. Melanoma

Answer 19

Answer : A

Question 20

All of the following are considered an increased risk factor for cancer in a patient with a thyroid mass except:
A. Age younger than 45 years
B. Rapid growth
C. Family history
D. Hot nodules on thyroid uptake scan
E. Male gender

Answer 20

Answer : D

Question 21

A 57-year-old female presents with a new diagnosis of a thyroid nodule. Routine workup includes all of the following except:
A. Physical examination
B. TSH
C. Cervical ultrasound
D. Thyroglobulin
E. Total thyroxine (T.)

Answer 21

Answer : D

Question 22

Calcitonin is produced by the parafollicular cells of the thyroid gland. Measurement of calcitonin is most useful in what disease process?
A. Pheochromocytoma
B. Follicular thyroid carcinoma
C. Hashimoto’s disease
D. MTC
E. Papillary thyroid carcinoma

Answer 22

Answer : D

Question 23

In the management of thyrotoxicosis, which of the following is correct?
A. lodine given in large doses stimulates the release of thyroid hormone.
B. A euthyroid state should be achieved through the use of antithyroid drugs before surgery.
C. Corticosteroids stimulate the peripheral conversion of Ta to T;-
D. ß-Blockers potentiate the effects of thyroid hormone through adrenergic stimulation of thyroid receptors.
E. Supersaturated potassium iodide (SSKI) should not be administered preoperatively.

Answer 23

Answer : B

Question 24

A 25-year-old woman at 10 weeks’ gestation has increasing shortness of breath and anxiety. The clinician wishes to screen her for hyperthyroidism. Which of the following statements is relevant to the interpretation of thyroid function in pregnant patients?
A. TBG is decreased and thus levels of total T, and T, are increased.
B. Decreased renal iodine clearance causes a reciprocal decrease in total T3.
C. Increased plasma volume decreases the total T, and T, levels measured in serum.
D. A first-trimester increase in human chorionic gonadotropin (hCG) causes a reciprocal decrease in TSH levels.
E. Thyrotoxicosis is relatively common in the first and second trimesters of pregnancy.

Answer 24

Answer : D

Question 25

A 37-year-old woman has an incidentally discovered thyroid mass on CT performed during a recent visit to the emergency department for workup of a fall at work. The patient undergoes neck ultrasonography. Which of the following features is less likely to be a malignant lesion? A. Incomplete halo B. Peripheral calcifications C. Hypoechoic lesion D. Irregular margins E. Size smaller than 2 cm

Answer 25

Answer : B

Question 26

The patient in Question 16 is found to have a 2-cm dominant nodule located in the right thyroid lobe. Cytologic evaluation of an FNA biopsy specimen reveals “atypia of undetermined significance.” All of the following are acceptable next steps in her management except: A. Right thyroid lobectomy B. Observation with repeat ultrasound and FNA in 6 months C. Right thyroid lobectomy with an intraoperative frozen section D. Radioactive iodine ablation E. Gene expression analysis of thyroid nodule FNA aspirate

Answer 26

Answer : D

Question 27

Overall, papillary thyroid carcinoma carries a favorable prognosis. Which of the following is not a prognostic risk factor in the tumor/node/metastasis (TNM) staging system? A. LN metastases B. Synchronous bone metastases C. Serum thyroglobulin level D. Extranodal extension E. Vascular invasion

Answer 27

ANSWER : C

Question 28

A 35-year-old man is newly diagnosed with MTC and is found to have an elevated calcitonin. In regard to the management of this patient, all are correct except: A. Preoperative ultrasound for LN mapping of the lateral and central compartments should be performed routinely. B. Biochemical screening for associated endocrinopathies (e.g., hyperparathyroidism or pheochromocytoma) is part of the preoperative workup. C. Treatment consists of total thyroidectomy with bilateral central node dissection. D. Measurement of CEA is not a useful marker of disease burden. E. Genetic counseling and screening should be offered to the patient and his immediate family members.

Answer 28

Answer : D

Question 29

Recent studies have shown that the incidence of thyroid cancer has nearly doubled in the last two decades. Plausible explanations given by epidemiologists include all of the following except: A. Childhood radiation exposure B. Iodine deficiency C. Estrogen hormone D. Increased use of diagnostic imaging modalities E. Increased use of thyroid function tests

Answer 29

Answer : E

Question 30

All of the following are true except T3 is the most active form of thyroid hormone Thyroid hormone is not involved in the fight or flight response Albumin carries the majority of thyroid hormone in circulation TSH is the most sensitive and accurate indicator of thyroid function (best test for either hyperthyroidism or hypothyroidism) A non-recurrent laryngeal nerve Is more common on the right

Answer 30

Answer c. Thyroxin-binding globulin (TBG) carries majority of T3 and T4.

Question 31

A 50 yo woman presents to your clinic with a thyroid nodule. After H and P, the most appropriate next step in management is: A-Thyroid lobectomy B-Total thyroidectomy C- FNA D- Neck MRI

Answer 31

Answer C. FNA (with U/S) is the best initial Dx test for a thyroid nodule.

Question 32

Ultrasound on the above patient reveals a 1.2 cm mass. Pathology from the FNA shows follicular cells. The most appropra next step in management is A- Thyroid lobectom b- Nothing C- Neck CT D- Neck MRI

Answer 32

Answer a. Follicular cells on FNA results in follicular cell CA in 5-10% of patients. Thyroid lobectomy is required for definitive Dx.

Question 33

You take the above patient to the operating room and perform a thyroid lobectomy. Pathology shows this is a 1.5 cm follicular cell carcinoma. The most appropriate next step is: A- Completion total thyroidectomy B- Close C- Post op chemotherapy d- Post-op XRT

Answer 33

Answer a. Follicular cell or papillary thyroid CA > 1 cm requires total thyroidectomy.

Question 34

The above patient also had palpable lymph nodes in her neck on physical exam prior to surgery. The most appropriate management is: a.Cherry pick the lymph nodes out of the neck b.Radical neck dissection C. Modified radical neck dissection (MRND) d. Post op XRT

Answer 34

Answer c. Patients with thyroid CA and clinically positive lymph nodes should undergo total thyroidectomy and MRND.

Question 35

After total thyroidectomy and MRND above, post-op this patient should also undergo: A. 1-131 therapy b. XRT C. Chemotherapy (5-FU) d. Tamoxifen therapy

Answer 35

Answer a. I-131 is indicated for either papillary and follicular thyrold CA > 1 cm.

Question 36

Post-operatively the above opera singer has a loss of voice pitch and voice fatigue. This is most likely due to injury of the: a.Superior laryngeal nerve b.Recurrent laryngeal nerve C.Vagus nerve D.Glossopharyngeal nerve

Answer 36

Answer a. Loss of pitch is most consistent with superior laryngeal nerve injury. Careful ligation of the superior thyrold artery branches at the level of the thyroid capsule can help avoid this complication.

Question 37

Instead of the above, the patient has a hoarse voice, most likely due to injury of the: A. Superior laryngeal nerve b. Recurrent laryngeal nerve C.Vagus nerve d.Glossopharyngeal nerve

Answer 37

Answer b. Hoarseness is most consistent with recurrent laryngeal nerve injury and abduction of the vocal cord. This nerve often tracks with the inferior thyroid artery inferiorly. The hoarseness may get better (wait 6-8 weeks); if that fails, medialize the vocal cord with a silicone wedge or silicone injection (not re-op repair of nerve).

Question 38

Post-op, a patient undergoing a difficult total thyroidectomy has severe respiratory stridor and impending respiratory arrest immediately after extubation in the post-anesthesia care unit. She does not have any signs of hematoma. The most effective way of airway access IS: a. Re-intubation b. Open the wound and place emergent tracheostomy C. Take her back to the OR for re-exploration D. Racemic epinephrine

Answer 38

Answer b. Given the clinical scenario, this patient likely suffered bilateral RLN injury. Trying to intubate a patient with bilateral RLN injury and medialization of both vocal cords (ie both cords are in a paramedian location) is very difficult. The best option is emergent tracheostomy through the collar incision (which you performed for the thyroidectomy). At times both vocal cords may be abducted, resulting in severe hoarseness and aspiration. Tracheostomy is needed in these patients as well.

Question 39

A 50 yo woman presents with a thyroid lump. You perform an U/S and it appears lo be a 1.5 cm cyst. The most appropriate next step is: a. Percutaneous cyst drainage B. I-131 C. Observation d. Thyroid lobectomy E. Thyroxine

Answer 39

Answer a. Percutaneous cyst drainage

Question 40

You completely drain the cyst in the above patient and send the fluid to pathology which shows serous fluid. One month later she retums to clinic with the same complaint and the cyst has returned on U/S. You drain it again and again one month later the cyst reappears. The most appropriate next step is: A. 1-131 B. Thyroxine C. XRT D. Thyroid lobectomy E. Methimazole

Answer 40

Answer d. Thyroid lobectomy Repeated occurrence of thyroid cyst is an indication for surgery (cyst size > 3-3.5, previous neck XRT. incomplete resolution, or bloody fluid are all indications for thyroid lobectomy (not cyst excision]) Cystic papillary thyroid CA can present with a recurrent cyst

Question 41

Following I-131, the most effective way of suppressing the growth of any residual follicular or papillary thyroid CA is a. Thyroid hormone replacement B. Daily calcium d. Daily phosphate replacement E. Daily potassium

Answer 41

Answer a. Thyrold hormone replacement following resection for thyroid CA is a very effective tumor suppressor adjunct By giving thyroid hormone, you effectively suppress TSH producton and inhibit tumor growth.

Question 42

A 50 yo woman with previous radiation therapy as a child has a 0.8 cm papillary thyroid CA. You do not feel any adenopathy. The most appropriate treatment is A. Thyroid lobectomy B. Total thyroidectomy C. Total thyroidectomy and MRND d. Observation

Answer 42

Answer b History of XRT is an indication for total thyroidectomy.

Question 43

Ali of the following are nsk factors for metastatic spread and recurrence of papillary and follicular thyroid CA except A. Males B. Previous XRT C. Age 20-50 d. Extra-capsular invasion

Answer 43

Answer c. RFs for thyroid CA metastases or recurrence: grade (poorly differentiated), age (< 20 or > 50), male gender, extra-thyroidal disease, size > 1 cm, previous XRT

Question 44

All of the following are true of medullary thyroid carcinoma (MTC) except A. Amyloid is found in the tissue b. Flushing and diarrhea occur C. Family members of patients with MEN lib should be screened for the RET proto-oncogene d. MEN lla patients have the worst prognosis

Answer 44

answer d. MEN Ilb and sporadic forms have the worst prognosis. Family members of patients with MEN Ilb should be screened for the RET prot oncogene. Screening using calcitonin is not recommended as these patients already have medullary thyroid CA

Question 45

Which of the following is true of MTC A. it is less aggressive than papillary or follicular thyroid CA b. Chemo is effective c I-131 is effective D. Total thyroidectomy, central node dissection, and ipsilateral MRND is indicated for patients who present with a palpable mass.

Answer 45

Answer d. Total thyroidectomy, central node dissection, and ipsilateral MRND is indicated for patients who present with a palpable mass. Chemo and 131I effective for MTC. MTC is more aggressive than papillary or follicular thyroid CA.

Question 46

All of the following are true of Hurthle cell thyroid tumors except. A. 80% are malignant B. MC occurs in elderly C. Pathology shows oncocytic or oxyphilic cells D. Diagnosis is usually made with lobectomy

Answer 46

Answer a. 80% of Hurthle cell thyroid tumors are benion.

Question 47

All of the following are true of anaplastic thyroid CA except a. Is usually resectable b. Usually presents in elderly patients with long-standing goiters C. Has a propensity to invade other structures D. Is the most aggressive thyroid CA

Answer 47

Answer a. Anaplastic thyroid CA is the most aggressive thyroid CA and is usually beyond surgical management at the time of Dx (5-YS - 5%).

Question 48

A 5 yo presents with a mid-line cervical mass that has had recurrent infections. The mass seems to move upward with swallowing. It also moves when the tongue is protruded. Which of the following is the most appropriate next step: A. Continued antibiotics B. Observation C. Resection of the cyst only D. Resection of the cyst and total thyroidectomy E. Resection of the cyst and the central portion of the hyold bone

Answer 48

Answer e. Tx for a thyroglossal duct cyst is resection of the cyst and the central portion of the hyoid bone.

Question 49

A 31 yo woman is 21 weeks pregnant and has severe tremors, tachycardia, and sweating. Her endocrinologist makes the diagnosis of hyperthyroidism and starts her on propyithlouracil (PTU), however, she continues to have Sx's. You advise the physician that the most appropriate next step is: A. Propranolol b. I-131 C. Thyroidectomy D. Switch to methimazole

Answer 49

Answer c. The problem in this patient is that you cannot use elther I-131 or methimazole because of their teratogenic effects. I-131 will ablate the fetal thyroid. Methimazole causes cretinism (stunted physical and mental growth due to hypothyroidism). Propylthiouracil (PTU) is safe because it does not cross the placenta. You could use a beta-blocker, but you would still have hyperthyroidism (albell with a lower heart rate) and an increased risk of stillbirth. Also, beta-blockers are contraindicated in the 3ª trimester of pregnancy as they have been associated with fetal growth retardation.

Question 50

All of the following are true except a. The Wolff Chaikoff effect is iodide inhibition of T3 and T4 release B. The mechanism of propyithiouracil Is inhibition of peroxidases and iodide binding C.The most appropriate initial Tx for thyroid storm is I -131 D. Serum thyroglobulin is the best lab value for detecting thyroid papillary or follicular cell CA recurrence E. Serum calcitonin is the best lab value for detecting recurrent medullary thyroid CA (MTC)

Answer 50

Answer c. The most appropriate initial Tx for thyroid storm is a beta-blocker (eg propranolol). High doses of iodine (Lugol's solution, potassium iodide) inhibit TSH action on the thyroid and inhibits organic coupling of iodide to tyrosine, resulting in less T3 and T4 release (Wolff-Chaikoff effect).

Question 51

All of the following are true except A. Follicular cell CA MC spreads hematogenously B. The MC thyroid CA in children is papillary thyroid CA C. Hashimoto's disease is a risk factor for thyroid lymphoma d. Psammoma bodies (calcium deposits) are most consistent with follicular e. The majority of substernal goiters can be removed with a cervical collar incision

Answer 51

Answer d. Psammoma bodies (calcium) are found in papillary thyroid CA.