Background: Benign-appearing cervical lymph nodes (CLN) are easy to assess during an ultrasonography (US) evaluation for a guided fine-needle aspiration biopsy of a suspicious thyroid nodule, but their clinical significance regarding thyroid cancer risk is not known. Non-malignant-appearing nodes may be an indicator of early malignancy in the thyroid. We hypothesize that there is an increased prediction of thyroid cancer when benign-appearing enlarged CLN (ECLN) > 1 cm in any dimension are present during an US evaluation of thyroid nodules.
Method: A review of 269 consecutive patients' charts sent for thyroid nodule assessment that underwent thyroidectomy was conducted to compare ECLN, with the presence of thyroid cancer during an ultrasound-guided fine-needle aspiration biopsy of the thyroid nodule. Surgical excision pathology confirmed all abnormal cytology reports.
Results: From the final 265 charts reviewed, 213 had benign thyroid pathology and 52 had thyroid cancer. Sex, number, and size of the biggest thyroid nodule were not different between groups. Patients with cancer were on average 10 years younger and had higher thyroid-stimulating hormone (TSH) values (p < 0.003) as well as a 10-fold increase in enlarged non-malignant-appearing lymph nodes than their peers without cancer. The presence of ECLN had an 82% sensitivity, 90% specificity, and a 68% positive predictive value for thyroid cancer. There was also an 80% negative predictive value when enlarged lymph nodes were not present. In 8 of the 37 (21.6%) patients with malignancy and ECLN, the primary dominant thyroid nodule was negative on cytologic evaluation, but malignancies were confirmed on surgical specimen, in contralateral nodules on the same side as the ECLN. These nodules were mostly subcentimeric, ranging from 0.2 to 1.14 cm and were not biopsied due to their inconspicuous appearance. After multiple logistic regression analysis, enlarged lymph nodes had a 53.8 odds ratio for cancer (20.49-141.33, p < 0.01).
Conclusion: Discovering the presence of ECLN in routine assessment of thyroid nodules is an easy and fast surveillance technique that increases the predictive value in diagnosing thyroid cancer, especially when the enlarged lymph nodes are on the same side as the thyroid nodule.