Ipsilateral and contralateral central lymph node metastasis in papillary thyroid cancer: patterns and predictive factors of nodal metastasis.

BACKGROUND: The aims of this study were to evaluate the rate and risk factors of ipsilateral and contralateral central lymph node (CLN) metastases in patients with papillary thyroid cancer (PTC).
METHODS: A total of 161 patients who underwent total thyroidectomy with prophylactic CLN dissection (CLND) to treat PTC were enrolled.
RESULTS: Of 134 total cases excluding tumors located in the isthmus and bilateral lobes, 72 cases (53.7%) involved CLN metastases. Tumor size, age, and sex were found to be predictive of ipsilateral CLN metastasis and the rate of ipsilateral CLN metastasis in tumors > 1 cm was 59.6%. Contralateral CLN metastases were more prevalent only in tumors that already had ipsilateral CLN metastases (27.3%, p = .002).
CONCLUSIONS: It is suggested that risk factors of ipsilateral and contralateral CLN metastases should be considered while planning the extent of CLND in patients with clinically node-negative and unilateral PTC upon preoperative ultrasonography.