Analysis of the Relationship between Central Cervical Lymph Node Metastasis from Papillary Thyroid Carcinoma and the Associated Factors according to the Tumor Size

ABSTRACT

PURPOSE: The aim of this study was to analyze the relationship between central lymph node metastasis and the associated factors in patients with papillary thyroid carcinoma (PTC) according to the tumor size, and we wanted to determine an appropriate treatment for PTC. METHODS: From June 2005 to May 2007, 218 patients with PTC underwent total thyroidectomy or lobectomy, and they also received central lymph node dissection at our institution. The patients were divided into three groups group 1 (tumor 10 mm). We retrospectively reviewed these patients to analyze the relationship between tumor size and the clinicopathological characteristics, including age, gender, lymph node metastasis, extrathyroidal extension, capsular invasion and lymphovascular invasion. RESULTS: There were 47 (21.6%) patients in group 1, 101 (46.3%) patients in group 2 and 70 (32.1%) patients in group 3. The tumor size was closely correlated with the presence of extrathyroidal extension, capsular invasion and lymph node metastasis (P<0.001). Lymph node metastasis was not only closely correlated with tumor size, but it was also significantly associated with extrathyroidal extension, capsular invasion and lymphovascular invasion (P<0.05). CONCLUSION: Our study confirmed that some factors, including central lymph node metastasis, capsular invasion and extrathyroidal extension, were frequently observed in patients with papillary thyroid microcarcinoma (PTMC), and central lymph node metastasis was related to tumor size, extrathyroidal extension, capsular invasion and lymphovascular invasion. Therefore, routine central lymph node dissection is recommended during the initial surgery for patients with PTMC.