Thyroid Nodules Flashcards
7 risk factors for a malignant thyroid cancer
- Age younger than 20 years or older than 70 years
- Male sex
- Associated symptoms of dysphagia or dysphonia
- History of neck irradiation
- Prior history of thyroid carcinoma
- Firm, hard, or immobile nodule
- Presence of cervical lymphadenopathy
What are 5 patient factors associated with a benign thyroid nodule
- Family history of autoimmune disease (eg, Hashimoto thyroiditis)
- Family history of benign thyroid nodule or goiter
- Presence of thyroid hormonal dysfunction (eg, hypothyroidism, hyperthyroidism)
- Pain or tenderness associated with nodule
- Soft, smooth, and mobile nodule
Lab testing to work up a thyroid nodule
- TSH is most important lab test
- Serum T3 and T4 might be helpful if TSH is normal, low-normal, high-normal
- If TSH is suppressed order a radionuclide thyroid scan (nodule in hyperthyroid pt is likely to be benign)
What is the role of plasma calcitonin in the work up of a patient with a thyroid nodule
Should be ordered if there is a family hx of medullary carcinoma or MEN2A or MEN2B
Describe a hot nodule
- Seen with hyperthyroidism (TSH is suppressed)
- Usually benign
- 99% of cases are hot nodules
- Takes up ALL the iodine, thyroid parenchyma is suppressed dt over-activity of nodule. Once kill nodule, rest of thyroid wakes up
Describe a cold nodule
- Seen in hypothyroidism (TSH is normal or high)
- Needs a biopsy
- Nodule does not take iodine
- 5-8% malignant
Describe a warm nodule
- In-between of cold and hot
- Nodule takes up MORE iodine but rest of tissue also takes it up
- Normal thyroid function
- 5-8% malignant
Explain the role of ultrasonography in the diagnostic work-up of a thyroid nodule
- this is one of the LOs I’m not sure I fully answered**
- Should be performed on all patients with known or suspected thyroid nodules
- Provides additional details: size, how echoic, calcifications, etc.
- Also used to assist FNAB
Explain the role of fine-needle aspiration biopsy in the diagnostic evaluation of thyroid nodules
- Highly accurate, accuracy does depend on cytopathologist’s expertise and experience and technical skills of physician performing biopsy.
- Cost effective compared to nuclear imaging and US
- Can reduce need for diagnostic thyroidectomy and increase yield of cancer dx
- Not all nodules need FNA, only those that are highly suspicious (hypoechoic, calcifications, irregular boarders, etc.)
- Never biopsy if <1 cm
name the FNAB diagnostic categories in the Bethesda System for Reporting Thyroid Cytopathology and the respective risk of malignancy associated each class
I. Non-diagnostic: 1-4%
II. Benign: 0-3%
III. Atypical follicular lesion of undetermined significance: 5-15%
IV. Follicular neoplasm/”suspicious” for follicular neoplasm: 15-30%
V. Suspicious for malignancy: 60-75%
VI. Malignant: 97-99%
Explain the role of using molecular testing in patients with indeterminate FNAB cytology
- this is one of the LOs I’m not sure I fully answered**
- Examines DNA of thyroid nodules to look for altered (cancerous) genes
- There is not currently one single optimal molecular test that can definitely rule in or out malignancy in all cases of indeterminate cytology
What thyroid nodule findings that warrant a surgical consult
- Follicular neoplasm (IV)
- Suspicious for malignancy (V)
- Malignant (VI)
What is the fu interval for patients with benign nodules
Follow with US at 6-18 month intervals with further intervention based on imaging features such as increased growth
What is the fu interval for patients with atypic nodules
- Repeat FNAB in 3-6 months. If again atypical, surgical consult is warranted
- If US exhibits worrisome characteristics (hypoechoic, irregular borders, calcifications, hypervascularity) then surgical consult warranted
For atypia nodules, identify the four ultrasound findings that warrant a surgical consult
- Hypoechoic,
- Irregular borders
- Calcifications
- Hypervascularity
