Evaluation
You find an incidental thyroid nodule on imaging - what lab and/or imaging do you order?
TSH -- normal or elevated means nonfunctioning nodule; low or suppressed TSH suggests primary hyperthyroidism
US of thyroid + cervical lymph nodes
If FNA or molecular test shows malignancy or suspicion for malignancy, how is patient treated?
SURGERY
-Low-risk micropapillary thyroid cancer <1 cm can be followed instead of surgery (without extrathyroid extension, metastatic cervical nodes, or distant mets), but should have active surveillance and have endocrine on board
If molecular testing not performed with FNA, patient's with indeterminate lesions should undergo ___
Diagnostic lobectomy
Since the introduction of this item in 1924, iodine deficiency has essentially been eliminated in the US
Iodized table salt
-What is a "hot" and "cold" nodule
-BONUS: Which needs FNA?
Hot: focal increased uptake, associated with hyperfunctioning - unlikely malignant, don't need FNA
Cold: Nonfunctioning, needs FNA if meets clinical/US criteria
How do you treat hyperfunctioning thyroid nodules?
Radioactive iodine ablation
-If contraindication or patient does not want, alternative is anti-thyroid therapy until euthyroid, then surgery to avoid lifelong thyroid med
True or False:
Thyroid nodules found in pregnancy have higher risk of being cancer
FALSE
-Nonfunctioning managed the same as nonpregnant except molecular testing
-Pregnant women with hyperfunctioning nodules should have antithyroid meds until after delivery, then should have radiouptake scans
This disease carries an increased incidence of papillary thyroid cancer
(33-42% prevalence in those with hypofunctioning thyroid nodules)
What are some US features that suggest malignancy?
Hypoechoic echogenicity
Solid
Irregular margins
Microcalcifications
Height > width
Extrathyroidal extension
Disrupted rim calcification
Cervical lymph nodes that are sus
FNA came back benign - do you repeat the FNA and when?
Yes, repeat in 12-24 mo
-If no clinical significant growth (>50% volume or 20% growth in 2 dimensions), can repeat every 3-5 years -- if grows, repeat FNA or serial US
True or False:
Thyroid nodules in children are more likely to be malignant than those in adults
TRUE - 22-26% increase risk
-Eval/tx is similar to adults, except molecular testing of FNA not validated so if indeterminate result, should have surgery
What percentage of thyroid nodules are benign?
90-95%
FNA should not be performed on nodules smaller than __
1 cm
-Micropapillary usually indolent/benign, but if less than 40 y/o, consider close follow up -- consider FNA anyway if young or if patient requests
-If smaller than 1 cm but have sus features, repeat US in 6-9 months
When to repeat cystic nodule screening?
Same time frame, can inject with ethanol or remove surgically if recurrent
True or False:
In patients with multiple thyroid nodules, each nodule has the same risk of malignancy
FALSE -- each nodule has an independent risk - biopsy the shadiest nodule(s) first and monitor the more benign ones
True or False:
You should routinely screen for thyroid cancer with US and/or neck palpation
FALSE
-Study in South Korea showed the diagnosis increased 15-fold, but no change to mortality rate
-USPSTF rec against it
DAILY DOUBLE
Cystic and spongiform nodules are rarely malignant and don't require FNA evaluation, EXCEPT if measure at ___ or larger.
Bonus: When do you re-US if no FNA?
2 cm
-Repeat US in 12-24 mo
Solid nodules benign on FNA - what do we do with them?
-Don't need to repeat FNA, even if it grows, but should consider removing and definitely should continue to follow w/ US
Patient has low to low-normal TSH and multiple nodules, what test do you order?
Radionuclide thyroid uptake scan! Figure out which ones need to be the targets for FNA
List 3 major risk factors for thyroid cancer
Ionizing radiation (cancer treatments, occupational exposure, nuclear fallout)
Radiation at a young age
Rapid nodule growth
Hoarseness
Family hx of thyroid cancer
Family hx of MEN2, FAP