Endocrinology Flashcards
(20 cards)
Decision tree for evaluating a thyroid nodule: what is the first step?
Check a TSH
Low TSH in evaluating a thyroid nodule: next steps and management
Thyroid scan, Free T4, Total T3
- Functioning ‘hot’ nodule: no FNAB, treat hyperthyroidism if indicated
- Nonfunctioning ‘cold/warm’ nodule: evaluate for US-guided FNAB
High or normal TSH on evaluation of thyroid nodule: next steps and management
Ultrasound
- > /= 1cm: evaluate for US-guided FNAB
- <1cm: repeat US in 6-24 moths
Which patients with subcentimeter thyroid nodule and normal or elevated TSH should undergo fine needle aspiration biopsy?
- Symptoms
- Pathologic lymphadenopathy
- Extrathyroidal extension
- h/o childhood radiation exopsure
- familial thyroid cancer syndrome
Which lab(s) to order initially in a patient with a goiter
Serum TSH
Patient with goiter, which study(ies) to perform if:
- Low TSH
- Normal TSH
- High TSH
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
What is the most common cause of diffuse goiter in the United States?
Autoimmune thyroid disease associated with thyroid dysfunction (Hashimoto thyroiditis, Grave’s disease)
When to repeat ultrasound for the following thyroid nodules:
- high-suspicion
- intermediate suspicion
- low suspicion
- very low suspicion
High: 6-12 months
Intermediate and low: 12-24 months
Very low: 24 months
When is a repeat FNA indicated for thyroid nodules?
All high-suspicion nodules
Nodules with concerning new sonographic findings
Intermediate or low suspicion nodules that increase significantly in size.
Papillary thyroid carcinoma vs follocular thyroid carcinoma:
- which is more common?
- where does each commonly spread?
PTC more common, spreads to cervical LNs.
FTC mets to lung, bone, other.
When to measure T3 with hypo or hyperthyroidism?
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
What is the differende between hyperthyroidism and thyrotoxicosis?
Thyrotoxicosis: high levels of T3 and T4 for any reason.
Hyperthyroidism: thyrotoxicosis caused by endogenous thyroid hormone production.
How to diagnose thyrotoxicosis?
Low TSH and elevated free T4 and/or total T3.
What is TRAb? What disease does it cause?
Antibody against TSH redeptor in the thyroid. Graves disease.
Treatment for Graves opthalmopathy:
Glucocorticoids, surgery, or teprotumumab. Doesnt respond to treatment of hyperthyroidism.
How cam amiodarone induce hyperthyroidism?
Iodine containing meds or contrast can turn a nontoxic thyroid adenoma into a toxic adenoma.
Three main treatment modalities for hyperthyroidism:
1) thionamides (methinazole, PTU)
2) radioactive iodine
3) thyroidectomy
First line treatment for Graves disease:
Thionamides. Methomzole unless first trimester pregnant due to risk of hepatic neceosis with propylthiouracil (PTU).
Most common cause of subclinical hyperthyroidism. When to treat?
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.
Initial management of subclinical hyperthyroidism:
Unless risk for complications (EG caediac disease), recheck TSH ~6 weeks.
