If the FNA results indicate that your thyroid nodule is benign, then congratulations are in order! Benign results are not 100% accurate and so it is still important that the thyroid nodule be evaluated for unusual growth over time. It is not uncommon for thyroid nodules to grow by 1-2 mm per year, but more than this amount of growth should definitively be reevaluated. Follow up ultrasound is the easiest way to evaluate for unusual nodule growth. This can be done at six month or annual intervals depending upon whether the nodule is stable. Most nodules grow very slowly and never need to be removed. However, thyroid nodules which exceed 4 cm will almost inevitably cause difficulties with swallowing; if they grow even larger, they will begin to push in on the airway. This airway compression is rarely noted by the patient. It first shows up as shortness of breath on exertion. Many patients attribute this shortness of breath to them being out of shape. Airway compression can easily be seen on ultrasound but looking for this is rarely a part of a routine ultrasound done at the hospital. The risks of thyroid surgery in an experienced thyroid surgeon’s hands are very low. However, even with the most experienced surgeon, the risk increases as the size of the nodule increases. So, if a thyroid nodule is clearly growing over time, it is better to be removed when it is large (>4cm) rather than when it becomes excessively large.
Even Benign Thyroid Enlargements can Cause Problems
A benign FNA is reassuring but doesn’t always mean that the nodule is not a problem. Large nodules can be life-threatening, even though they are benign. Benign means that there is no risk of spread outside the thyroid, but it doesn’t always mean there are no risks! Recently, we removed an 18 cm lobe from a lady who had severe airway compression. This operation could have been done years earlier and the delay in referral for this enormous goiter only increased her surgical risks! To make matters worse, she had a prior lobectomy on the other side, done by a general surgeon who had paralyzed her vocal cord nerve. This case was made even more challenging because this massive thyroid had grown into the chest and was pushing on the arch of the aorta! Thankfully, everything went well, and we removed her thyroid lobe without any complications. However, her delay in referral, her prior experience with a low-volume surgeon, and her attributing her shortness of breath to her weight, all led to a higher-risk operation than it needed to be!
When your FNA Indicates Cancer
If the thyroid FNA returns cancer or suspicion for cancer, then surgical treatment is the recommended choice. There are no other treatment options which come even close to the high cure rates that are obtained by thyroid surgery. Most common forms of thyroid cancer have very high cure rates, especially when diagnosed early. While the prognosis for most people with thyroid cancer is very good, the rate of recurrence or persistence can be up to 30% and recurrences can occur even decades after the initial treatment. For more information on thyroid cancer, click here.
When your FNA is Indeterminant
If the FNA results are indeterminant, then decision making becomes much more complex. Whether molecular testing, repeat serial ultrasounds and observation over time, or surgery is recommended, it is highly individualized. Certainly, ultrasound characteristics should be taken into account when evaluating next steps for an indeterminant lesion. An experienced thyroid surgeon can guide the patient to decisions which lower risk and provide better outcomes.