Surgical approach to cervical lymph node metastasis in differentiated thyroid cancer

Precautionary locoregional lymph node dissection in thyroid carcinomas for diagnostic and/or staging purposes is useless both in differentiated (papillary and follicular) and undifferentiated forms. It is only indicated in medullary carcinomas because of their frequent spread to regional lymph nodes. The objective of lymphadenectomy is to contain tumor spread; however, the procedure may be associated with intraoperative complications and postoperative sequelae. In order to improve the therapeutic management of patients with thyroid carcinoma, diagnostic scintigraphy with 201T1 or 99mTc-sestamibi is used in the advanced and undifferentiated forms of this tumor.

We have treated a woman submitted three years previously to total thyroidectomy for papillary carcinoma (pT3) without subsequent radiometabolic treatment. On physical examination we noted a swelling on the left side of the neck. The lesion was confirmed by ultrasonography, CT scan, and scintigraphic examination with 99mTc-sestamibi 24 hours before planned lymphadenectomy. During the surgical procedure we performed radiodetection to localize metastatic lesions.

Intraoperative radiodetection may help to identify residual disease, which is often difficult to trace in the presence of post-surgical fibrosis. In our patient, histological examination of the removed tissue specimens demonstrated that intraoperative radiolocalization had been highly accurate. The eradication of residual disease was confirmed by scintigraphic follow-up after 12 months.

Scintigraphy with 99mTc-sestamibi has been proposed as a means to localize metastatic spread and possible residual disease after a supposedly radical thyroidectomy. Surgical eradication of all residual tumor guarantees the best disease control without having to resort to radiometabolic therapy. This approach will reduce the incidence of iatrogenic comorbidity and consequently improve the patients' quality of life.