Removing lymph nodes in thyroid surgery is not done by every thyroid surgeon, but should be in most circumstances.  To better understand why, lymph nodes in the neck are a charcoal filter system, for lack of a better term.  The problem with our human body and thyroid cancer, is that thyroid cancer cells can break out early from the thyroid gland and spread to these local lymph node (filters).  The cells then slowly grow within these filters, but the body cannot clear them. 

In most circumstances, removing the thyroid cancer and these local lymph nodes cures the far majority of thyroid cancers. But this even becomes more complicated because despite advances in our ability to identify thyroid cancers before surgery, nearly 50% of thyroid cancers are not known until following their initial thyroid operation.  Whether you have thyroid cancer or require a thyroid operation for non-cancer reasons, you only want to have one expert thyroid operation!!!  Persistent or recurrent thyroid cancer is often a preventable event if the right operation is performed.  To better understand this, here are the 4 Reasons lymph nodes are a big deal in thyroid surgery.

The Four Reasons Lymph Nodes are a Big Deal in Thyroid Surgery

#1 Reason Lymph Nodes are a Big Deal in Thyroid Surgery:  The Most Common Thyroid Cancers Have A High Risk of Lymph Node Spread in the Neck

Lymph nodes are the “charcoal filtration system” of the body.  In fact, if the thyroid cancer does not spread to lymph nodes, the likelihood or potential for it to spread to other sites in the body is very low. Because of this, the evaluation, detection and removal of thyroid cancer involved lymph nodes tells both the patient and the doctor tremendously valuable information.  Since lymph nodes are the first location that thyroid cancer can spread, expert evaluation of the lymph nodes at risk in thyroid cancer is the critical first step in the evaluation of a patient with a thyroid cancer or a thyroid nodule (which may, or may not be a thyroid cancer).

#2. Reason Lymph Nodes are a Big Deal in Thyroid Surgery:  Once thyroid cancer has spread to neck lymph nodes, the body cannot clear the thyroid cancer cells and the thyroid cancer will begin to grow within those lymph nodes.

Expert ultrasound evaluation of any thyroid cancer or thyroid nodule is required in all patients.  This examination is called a comprehensive high resolution ultrasound and requires tremendous expertise and time.  If the high resolution ultrasound only examines the thyroid gland and surrounding area, it is an incomplete examination!   Unfortunately, however, even today, incomplete and unskilled ultrasound examinations of the neck are commonplace in the evaluation of thyroid patients.

An expert high resolution ultrasound has the ability to detect lymph nodes in the side of the neck with as little as 1-2 mm of thyroid cancer spread.  If there is no detection of suspicious lymph nodes in the side of the neck, the lymph nodes at highest risk of containing thyroid cancer lay behind and surround the thyroid gland.  Most of these lymph nodes are difficult or not possible to examine when the thyroid remains in its natural location.  Further, enlarged thyroid glands can block the ability to even examine these lymph nodes with ultrasound since they may completely cover them.

As thyroid cancers enlarge, the risk of lymph node involvement increases.  In the most common type of thyroid cancer, papillary thyroid cancer, the risk of lymph node involvement in a 1 cm cancer is reported to be in the 15-20 percent range.  In contrast, papillary thyroid cancers greater than 4 cm have a risk of lymph node involvement in around 90%.  One of the most common genetic events of papillary thyroid cancer is a mutation of a gene called BRAF.  BRAF mutation in papillary thyroid cancer is truly not a “bad” mutation, however it does predict the high risk of lymph node involvement in papillary thyroid cancers possessing that mutation.

In our approach to papillary thyroid cancers and those thyroid nodules which may or may not be thyroid cancer, the lymph nodes behind and around the thyroid gland are routinely removed. In this manner, microscopically involved lymph nodes are removed and can be diagnosed during thyroid surgery. If these lymph nodes are not removed during thyroid surgery and possess microscopic cancer cells, the thyroid cancers will grow within these lymph nodes and become detectable with time and lead to further surgery and recurrence of thyroid cancer.  Our approach to thyroid cancer surgery provides our patients the lowest rate of persistent or recurrent thyroid cancer in the literature.

Figure 1: Red arrow in this CAT scan shows a right papillary  thyroid cancer and the yellow arrow is pointing to a small neck lymph where the thyroid cancer has spread.

#3 Reason Lymph Nodes are a Big Deal in Thyroid Surgery:  Removing lymph nodes prevents recurrence of your thyroid cancer and provides the highest Cure Rates

Removal of the lymph nodes behind and surrounding the thyroid gland is both a very important therapy as well as helps in the diagnosis of thyroid cancer.  These lymph nodes are analyzed by our expert thyroid pathologists during the operation.  The information is tremendously important to the patient and the patient’s outcome.  Further, the information determines whether the operation is complete or whether additional surgery may be indicated to cure the patient.

In the operation which includes removal of the lymph nodes behind and surrounding the thyroid gland, the pathologic analysis of those lymph nodes can tell the following:

1. If the lymph nodes are without cancer, either the thyroid has a thyroid cancer which has not spread to lymph nodes or there is no cancer in the thyroid gland.
2. If the one or two lymph nodes have microscopic thyroid cancer within them, then the thyroid gland has a small cancer which has been cured and requires no more treatment.
3. If multiple lymph nodes throughout one side of the thyroid gland have cancer or the cancer within the lymph nodes are large and has completely overtaken the lymph node or spread outside of the covering of the lymph node, then the other lymph nodes surrounding the other side of the thyroid are at similar risk and should be removed. This is generally when radioactive iodine may be considered.

Figure 2: An ultrasound of a 19 year young female patient with a 4 mm ( less than ¼ inch) papillary thyroid cancer of the center portion of her gland.  There is a small lymph node which is being measured underneath the right side of the thyroid gland and is suspicious for thyroid cancer which has spread to a lymph node.  Surgery confirmed fifteen of her 31 lymph nodes underneath and surrounding her thyroid gland had detectable metastatic thyroid cancer.

Very importantly, thyroid cancer patients and thyroid patients should always seek to be managed with only one surgical procedure.  A surgical procedure which commits a thyroid patient to more than a single surgical procedure is clearly an inferior operation for any patient.

#4 Reason Lymph Nodes are a Big Deal in Thyroid Surgery:  Nearly 50% of Thyroid Cancers Are Not Known to be Thyroid Cancer Until Following an Operation.

Despite contemporary ultrasound, needle biopsy and genetic analysis of thyroid nodules, nearly 50% of thyroid cancers are not diagnosed until the final pathology diagnosis of thyroid surgery has been obtained. In most circumstances, that takes approximately one week following the thyroid operation.  Therefore, all surgery for thyroid nodules of uncertain potential to be cancer, should be performed as if they are a thyroid cancer.

When a patient has a thyroid nodule and is going to undergo an operation, the surgical procedure must be planned to definitively manage a thyroid cancer.  This does not mean it needs to be an aggressive surgery whatsoever.  In fact, it is often a “less aggressive” surgical procedure which can spare normal thyroid tissue.  Let’s give an example.  A patient has been followed for a thyroid nodule which has been biopsied benign on two separate occasions.  However, the thyroid nodule has continued to progress in size and it is now 3 cm in greatest dimension.  (a little more than an inch long).  The patient undergoes an operation which removes the right side of the thyroid gland with the 3 cm lump and the lymph nodes behind the thyroid gland.  During the operation, our pathologist confirms 1 of the eleven lymph nodes revealed a microscopic focus of papillary thyroid cancer.  The patient requires no more surgery and has been cured of his malignancy.  The patient does not require radioactive iodine therapy or any further operation.   No surprisingly, one week following the operation, the final pathology of the thyroid nodule is returned and reveals a classical papillary thyroid cancer. 

The operation has cured the patient and there is no role for additional treatment such as radioactive iodine therapy. 

Why was the needle biopsy previously benign?  There can be many reasons.  First, the needle must be introduced through normal thyroid tissue and these cells may convince the cytologist of the benign nature.  Second, sometimes the thyroid nodules have sampling bias where a particular portion of the nodule may not completely represent the tumor.  Third, the cytologist reviewing the needle biopsy may not be a thyroid cytology expert.  Fourth, certain contents of the needle biopsy may convince the cytologist that the aspirate is benign. 

Bonus: Why Lymph Nodes Are A Big Deal in Thyroid Surgery #5

Expert thyroid cancer surgical care is required to achieve the best cure rate and lowest complication rate for thyroid cancer.  Not every surgeon should be doing thyroid surgery.  Unfortunately, 90 percent of thyroid surgery in this country is accomplished by surgeons that only do about 10 thyroid operations a year.  In contrast, we advocate for super subspecialization in thyroid surgery.  Do one type of surgery and do it quicker, better, and with less complications than others.  Because the lymph nodes beneath the thyroid gland surround the nerves to the voice box and the parathyroid glands that control calcium (parathyroid glands), only expert surgeons should be performing these operations.  A thyroid surgeon that performs 400 or more thyroid operations per year is significantly experienced in about five years of practice to manage these types of operations. 

What to do if you need expert thyroid surgery?

If you have a lump in your thyroid gland or need an expert thyroid surgeon, you should seek expert evaluation by a thyroid cancer expert.  This may be a thyroid cancer surgeon or an endocrinologist who has expertise in the evaluation and management of individuals with thyroid cancer.  Do your homework.  Be your own advocate.  Check Google and Healthgrade reviews.  Speak to doctors and other health care professional in  your local area.  The evaluation includes:

1. A comprehensive history and physical examination.
2. Examination of the voice box to examine its appearance and how the vocal cords are working.
3. A high resolution ultrasound of the thyroid gland and neck lymph nodes
4. Special blood testing looking at the function of the thyroid gland as well as specific proteins that can be produced by thyroid cancers and found in the blood
5. Biopsy of the thyroid or lymph nodes of the neck with a tiny needle know as Fine Needle Aspiration biopsy or FNA
6. CAT scan (also known as CT scan) may also be used in people with very large thyroid masses or cancers or when disease is concerned to be in locations not well examined by the ultrasound of the thyroid and neck.

Want more information about thyroid surgery and thyroid cancer?  Check out our other blogs and website at ThyroidCancer.com. 

Suggested reading:

Management of the central compartment in differentiated thyroid carcinoma. Goepfert RP, Clayman GL. Eur J Surg Oncol. 2018 Mar;44(3):327-331.

Role of preoperative ultrasonography in the surgical management of patients with thyroid cancer. Kouvaraki MA, Shapiro SE, Fornage BD, Edeiken-Monro BS, Sherman SI, Vassilopoulou-Sellin R, Lee JE, Evans DB. Surgery. 2003 Dec;134(6):946-54.

In papillary thyroid cancer, preoperative central neck ultrasound detects only macroscopic surgical disease, but negative findings predict excellent long-term regional control and survival. Moreno MA, Edeiken-Monroe BS, Siegel ER, Sherman SI, Clayman GL. Thyroid. 2012 Apr; 22(4):347-55. doi: 10.1089/thy.2011.0121. Epub 2012 Jan 26.

Is There a Minimum Number of Thyroidectomies a Surgeon Should Perform to Optimize Patient Outcomes? Adam MA, Thomas S, Youngwirth L et al. Annals of Surgery. Feb 2017; 265,2:402–407.

A national cancer data base report on 53856 cases of thyroid carcinoma treated in the US, 1985–1995. Hundahl, SA, Fleming, ID, Fremgen, AM et al. Cancer. 1998; 83: 2638–2648.

Additional Resources

• Become our patient at www.thyroidcancer.com/become-a-patient
• More about the The Clayman Thyroid Center at thyroidcancer.com/about
• More about the Hospital for Endocrine Surgery
• Scarless Thyroid Surgery for thyroid cancer