Thyroid

Question 1

The most metabolically active thyroid hormone is

Answer 1

Triiodothyronine

Question 2

MC cause of hypothyroidism in the US

Answer 2

Autoimmune thyroiditis

Question 3

Inhibitors of thyroid secretion, function, and metabolism include all except: 
A. estrogen
B. growth hormone
C. dopamine
D. cortisol
E. somatostatin

Answer 3

B. growth hormone

Question 4

Tremors, nervousness, and inc HR can be sx of all myxedema coma. T/F

Answer 4

False

Question 5

Which statement is not true of thyroid parafollicular cells?
A. secrete a peptide hormone involved in inhibiting bone resorption
B. Are the cell type found proliferating in medullary thyroid cancers
C. Contain Na/I symporter
D. Found in spaces between thyroid follicles

Answer 5

C. contain Na/I symporter

These are only found on thyroid follicular cells, which concentrate iodine

Question 6

44 yo F with hx pernicious anemia PTC c/o anxiety and palpitations with unexplained weight loss of 10 lb and multiple daily BM. Also amenorrhea.
Thyroid bruit and 4x3 cm oval, nontender, soft-tissue mass lateral to thyroid cartilage.
Dx?

Answer 6

Toxic thyroid adenoma

Question 7

In Grave’s disease:

• High TSH
• High fT3/fT4
• High TPOAB

Answer 7

False

TSH is suppressed

Question 8

Thyroglossal duct cysts are nearly always malignant

Answer 8

False

Question 9

WHO iodine RDA for adult men and non-pregnant women

Answer 9

150 mcg

Question 10

Diarrhea is common in hyper/hypothyroidism

Answer 10

Hyperthyroidism

Question 11

Grave’s disease is assoc with which autoantibodies

Answer 11

anti-TSH antibodies

Question 12

Features associated with cretinism

Answer 12

Delayed mental development
Short stature
Delayed puberty
Myxedema

Question 13

Which common mineral supplement can interfere with levothyroxine absorption?

Answer 13

Magnesium

Question 14

TSH 0.3 
fT4 0.6 (0.8-1.8)
fT3 2.5 (2.3-4.2)
No antibodies
Dx?

Answer 14

Central hypothyroidism

Question 15

Which is most true with malignant thyroid nodules?
A. MC in older women wit multinodular goiter
B. MC in young men than older men
C. More likely to be “hot” than “cold”
D. typically cystic rather than solid

Answer 15

B. More likely in young men than older men

Question 16

Which statement is true of thyroid cancer:
A. Medullary carcinoma is MC thyroid cancer
B. Anaplastic thyroid carcinoma has 5 yr survival rate > 80% following tx
C. Papillary thyroid cancer tends to have mets via lymph nodes instead of blood
D. All thyroid masses < 1 cm should be referred for fine needle aspiration

Answer 16

C. Papillary thyroid cancer tends to have mets via lymph nodes instead of blood

Question 17

What are possible drug therapies in Grave’s disease?

Answer 17

Methimazole
I-131 therapy
Propranolol

Question 18

If the following condition is present in a patient wtih hypothyroidism, appropriate tx must be started before starting thyroid replacement (to prevent circulatory collapse): 
A. Hypoparathyroidism
B. Addison's disease 
C. Pituitary dwarfism
D. Cushing's disease
E. Acromegaly

Answer 18

B. Addison’s disease

Often causes elevated TSH (mimics hypothyroidism)

Question 19

45 yo F PTC with fatigue, inc appetite, diaphoresis, and palpitations.
Eyes are protruding.
She starts meds, but soon develops fever and repeated pharyngitis/GI infections.
Which med is it and what is the reaction?

Answer 19

Propylthiouracil (PTU) for Grave’s disease

< 0.5% incidence of agranulocytosis

Question 20

Follicular hyperkeratosis is directly related to serum deficiency of

Answer 20

Vitamin A

poor conversion of beta-carotene to vitamin A