Endocrinology

Question 1

Decision tree for evaluating a thyroid nodule: what is the first step?

Answer 1

Check a TSH

Question 2

Low TSH in evaluating a thyroid nodule: next steps and management

Answer 2

Thyroid scan, Free T4, Total T3

• Functioning ‘hot’ nodule: no FNAB, treat hyperthyroidism if indicated
• Nonfunctioning ‘cold/warm’ nodule: evaluate for US-guided FNAB

Question 3

High or normal TSH on evaluation of thyroid nodule: next steps and management

Answer 3

Ultrasound

• > /= 1cm: evaluate for US-guided FNAB
• <1cm: repeat US in 6-24 moths

Question 4

Which patients with subcentimeter thyroid nodule and normal or elevated TSH should undergo fine needle aspiration biopsy?

Answer 4

• Symptoms
• Pathologic lymphadenopathy
• Extrathyroidal extension
• h/o childhood radiation exopsure
• familial thyroid cancer syndrome

Question 5

Which lab(s) to order initially in a patient with a goiter

Answer 5

Serum TSH

Question 6

Patient with goiter, which study(ies) to perform if:

• Low TSH
• Normal TSH
• High TSH

Answer 6

Low TSH and goiter: 
-free T4, total T3
-thyroid scintigraphy
Normal or High TSH and goiter:
-thyroid-neck ultrasound at risk for thyroid cancer or palpable thyroid nodules, gland asymetry, large goiter, rapid growth, or compressive symptoms

Question 7

What is the most common cause of diffuse goiter in the United States?

Answer 7

Autoimmune thyroid disease associated with thyroid dysfunction (Hashimoto thyroiditis, Grave’s disease)

Question 8

When to repeat ultrasound for the following thyroid nodules:

• high-suspicion
• intermediate suspicion
• low suspicion
• very low suspicion

Answer 8

High: 6-12 months
Intermediate and low: 12-24 months
Very low: 24 months

Question 9

When is a repeat FNA indicated for thyroid nodules?

Answer 9

All high-suspicion nodules
Nodules with concerning new sonographic findings
Intermediate or low suspicion nodules that increase significantly in size.

Question 10

Papillary thyroid carcinoma vs follocular thyroid carcinoma:

• which is more common?
• where does each commonly spread?

Answer 10

PTC more common, spreads to cervical LNs.

FTC mets to lung, bone, other.

Question 11

When to measure T3 with hypo or hyperthyroidism?

Answer 11

Hypo: usually dont measure. Only low in severe hypothyroidism.
Hyper:
1) Identify isolated T3 toxicosis
2) Evaluation of hyperthyroidism severity and therapeutic response
3) differentiation of hyperthyroidism from destructive thyroiditis

Question 12

What is the differende between hyperthyroidism and thyrotoxicosis?

Answer 12

Thyrotoxicosis: high levels of T3 and T4 for any reason.
Hyperthyroidism: thyrotoxicosis caused by endogenous thyroid hormone production.

Question 13

How to diagnose thyrotoxicosis?

Answer 13

Low TSH and elevated free T4 and/or total T3.

Question 14

What is TRAb? What disease does it cause?

Answer 14

Antibody against TSH redeptor in the thyroid. Graves disease.

Question 15

Treatment for Graves opthalmopathy:

Answer 15

Glucocorticoids, surgery, or teprotumumab. Doesnt respond to treatment of hyperthyroidism.

Question 16

How cam amiodarone induce hyperthyroidism?

Answer 16

Iodine containing meds or contrast can turn a nontoxic thyroid adenoma into a toxic adenoma.

Question 17

Three main treatment modalities for hyperthyroidism:

Answer 17

1) thionamides (methinazole, PTU)
2) radioactive iodine
3) thyroidectomy

Question 18

First line treatment for Graves disease:

Answer 18

Thionamides. Methomzole unless first trimester pregnant due to risk of hepatic neceosis with propylthiouracil (PTU).

Question 19

Most common cause of subclinical hyperthyroidism. When to treat?

Answer 19

Multinodular goiter. Treat when thyroid-stimulating hormone level less than 0.1 μU/mL (0.1 mU/L), cardiac risk factors, heart disease, high risk for osteoporosis, or symptoms.

Question 20

Initial management of subclinical hyperthyroidism:

Answer 20

Unless risk for complications (EG caediac disease), recheck TSH ~6 weeks.