RESUMEN
The cervical lymph node metastasis is a risk factor for the high recurrence rate and low survival rate in patients with thyroid carcinoma (especially for age ≥45 years old), which is the most common head and neck carcinoma. The neck lymphatic metastasis, mostly occurring in the central neck compare, is diagnosed among 20%-90% of patients with differentiated thyroid carcinoma. To definite the anatomic boundaries of the central lymph nodes and their subgroups is significantly important for thyroid carcinoma, such as the determination of surgical extent, the evaluation of prognosis and the choice of different treatment strategies. This paper aims to describe the anatomic boundaries and the components of the central neck compartment and the role of individual subgroups in thyroid carcinoma. We think that the central neck compartment is bounded superiorly by the hyoid bone, inferiorly by the innominate artery on the right and the corresponding axial plane on the left, laterally by the carotid arteries. The superior mediastinal lymph nodes should be the important subgroups of the central neck compartment in thyroid carcinoma. When the prophylactic central lymph node dissection for involved lymph nodes is performed in thyroid carcinoma, we should pay more attention to the superior mediastinal lymph nodes.
RESUMEN
Objective:To analyze the factors related to metastasis of contralateral central lymph node (CLN) in cN0 papillary thyroid car-cinoma (PTC) and discuss the indications for CLN dissection. Methods:We enrolled 149 unilateral PTC patients who underwent total thyroidectomy and prophylactic bilateral (CLN) dissection. This work analyzed the relationship of gender, age, extrathyroidal extension, multifocality, thyroiditis, ipsilateral central lymph nodes, and prelaryngeal lymph node with CLNs. Results:The rates of metastasis to ip-silateral and contralateral central compartments were 73.2%and 23.5%, respectively. In univariate analysis, gender, age, tumor size, multifocality, and thyroiditis were not important in predicting contralateral central compartment lymph node metastasis (P=0.792, 0.097, 0.531, 0.269, and 1.000, respectively);by contrast, extrathyroidal extension (P=0.017), prelaryngeal lymph nodes (P=0.006), and ipsilateral CLNs (P<0.001) are related to CLN metastasis. However, multivariate analysis showed that ipsilateral central metastasis was an independent risk factor for lymph node metastasis in the contralateral central region when the number of ipsilateral central metas-tases is≥3 (P=0.010). Conclusion:Extracapsular invasion, prelaryngeal lymph nodes, and ipsilateral CLN influence the metastases of CLN. Bilateral CLN dissection should be performed when the number of ipsilateral central metastases is≥3 and there is merger of ex-tra-laryngeal lymph nodes or capsule invasion.