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Page 2 of 9 Shaha. J Cancer Metastasis Treat 2023;9:22 https://dx.doi.org/10.20517/2394-4722.2022.101

[1]
has risen almost 15 times Neck node metastasis is fairly common in papillary thyroid carcinomas, with an
[2,3]
incidence ranging between 40%-60% , however, nodal metastasis does not significantly impact overall
prognosis or long-term outcome. Nonetheless, it does have a direct impact on the identification of the
disease, surgical procedure and repeated surgical procedures for multiply recurrent neck node metastasis
leading to surgical complications rather than overall outcome difference. It should be noted that there is a
difference between clinically palpable disease and radiologically identifiable disease or biochemically
identifiable disease in the recurrent setup. Biochemically identifiable disease in the recurrent setup has no
definite prognostic implication, and small-volume recurrent disease such as that documented on ultrasound
or CT scan likewise has very little prognostic significance. Sonographic documentation of 1 cm or less nodal
metastasis generally is not of major concern unless it is plastered against the trachea or in the tracheo-
esophageal groove directly against the recurrent laryngeal nerve. Bulky nodal metastasis and further
recurrences with extranodal spread that may involve the soft tissues in the neck significantly affect long-
term outcomes. There are many controversial issues surrounding the management of neck node metastasis,
as outlined in Table 1.

In the past, the major controversy in thyroid cancer management revolved around the extent of
thyroidectomy: lobectomy versus total thyroidectomy. The focus of debate has now shifted to prophylactic
central compartment dissection and the extent of lateral neck node dissection. This controversy likely
originated in 2006 when the American Thyroid Association (ATA) guidelines suggested elective
[4]
prophylactic central compartment dissection in patients with papillary carcinoma . It was soon recognized
that this resulted in an increased number of complications related to temporary or permanent
hypoparathyroidism and recurrent laryngeal nerve injury with no definite outcome benefit. In 2009, the
guidelines were revised to recommend elective central compartment dissection only in high-risk patients
presenting with larger tumors, gross extrathyroidal extension, or aggressive histology . This is an important
[5]
paradigm shift with practical implications for the management of neck node metastasis.

DIAGNOSTIC EVALUATION
Clinical examination, evaluating the primary tumor and neck from the high jugulodigastric area to the
paratracheal region, is extremely critical. However, there is clearly a difference between clinically apparent
disease and disease identified by imaging. The most important imaging studies are ultrasound, ultrasound-
guided needle biopsy, CT scan with contrast, MRI, PET scan, and RAI ablative scan. The ultrasound is a key
investigation in the evaluation of both primary and neck nodes. The characteristic features of neck nodes
which will render the suspicious diagnosis of metastatic thyroid cancer include irregularity,
hypervascularity, loss of fatty hilum, extranodal extension, and calcification. Prior to any definitive surgical
intervention, it is appropriate to confirm the presence of metastatic disease with an ultrasound-guided
needle biopsy. There is considerable interest in thyroglobulin wash in needle biopsy aspirants, high
thyroglobulin levels are a clear indication of metastatic thyroid carcinoma. CT scan with contrast is
extremely helpful to evaluate certain critical areas such as the jugulodigastric, supraclavicular, and posterior
triangle regions, and more importantly, central compartment evaluation including levels VI and VII,
retropharyngeal and parapharyngeal lymph node metastasis. Routine ultrasound is unlikely to identify these
specific areas and the CT scan with contrast should be an important preoperative investigation. The CT
scan will also give a better determination of the extent of the primary disease including the substernal
extension and adherence to the surrounding structures such as larynx and trachea . This is more
[6,7]
important to localize the extent of the disease in the tracheo-esophageal groove and its adherence to the
trachea or the esophagus. While MRI is also an important investigation, the CT scan offers a better
perception and clarity of the extent of the disease. CT scan should be performed with contrast and the