Lymph node ultrasound before thyroidectomy

A woman was sent to me for ultrasound-guided fine-needle aspiration biopsy of a thyroid nodule. As is my usual practice prior to the biopsy, I performed detailed ultrasound evaluation for cervical lymphadenopathy.

Lateral to the carotid and across from the thyroid nodule, there was a level IV lymph node highly suspicious for metastasis not described on the initial thyroid ultrasound report. It had a heterogenous echotexture and increased chaotic flow, both of which were concerning. I usually biopsy suspicious lymph nodes in patients with thyroid nodules. However, this lymph node was located directly behind the jugular, making my usual anterior approach impossible. I decided to biopsy the thyroid nodule only.

The fine-needle aspiration was positive for papillary thyroid cancer. I sent the patient to the surgeon with a request that the suspicious lymph node and any others be resected during the initial procedure. However, I was surprised to see no lymph nodes mentioned in the pathology report. The surgeon did not remove any lymph nodes because none appeared abnormal on inspection.

At her follow-up appointment, I discussed our options. In the past, before high-resolution ultrasound became available, we would have simply treated with radioactive iodine. Now we prefer to resect confirmed or suspicious metastatic lymph nodes whenever possible.

It is estimated that 30% to 90% of patients with papillary thyroid cancer have metastasis or micro-metastasis at the time of diagnosis. Those with lymph node metastasis have a higher recurrence rate which appears to be reduced by lymph node dissection. The American Thyroid Association recommends routine central compartment (level VI) lymph node dissection in most patients with papillary thyroid cancer. Lateral compartment (level II, III, IV and V) dissection is advised in patients with lymph node metastasis. These recommendations are echoed by the National Comprehensive Cancer Network and others.

As noted by Davidson et al, metastasis to a single lymph node is unusual. Removal of single metastatic lymph nodes was associated with a high recurrence rate (86.6%). Therefore, compartmental dissection is preferred over “berry picking.”

Lymphadenectomy may also reduce mortality, but the data are limited. The majority of patients with papillary thyroid cancer, even those with cervical lymph node metastasis, have an excellent long-term prognosis. Thus, it is challenging to evaluate the effects of various management approaches.

The patient and I agreed that metastatic disease should be removed prior to radioiodine ablation. Before undergoing additional surgery, we needed to confirm that this was truly metastasis. The problem was that it was directly behind the jugular and impossible to biopsy by my typical approach with the needle held perpendicular to the ultrasound probe. Instead, I came in laterally and underneath the jugular. I held the ultrasound probe parallel over the needle, so that I could visualize it at all times and avoid puncturing either of the blood vessels.

The thyroglobulin washout was 1,791 ng/mL and the fine-needle aspiration was positive for metastatic papillary thyroid cancer. She will be undergoing lymph node dissection to be later followed by radioactive iodine.

Metastatic lymph node.

Lymph node on fine-needle aspiration.

Courtesy of Thomas Repas,
DO, FACP, FACE, CDE

Cooper DS. Thyroid. 2006;16:1-33.

Davidson HC. Laryngoscope. 2008;118:2161-2165.