Risk factors for central and lateral lymph node metastasis in papillary thyroid carcinoma

Background: Lymph node metastasis (LNM) is commonly observed in papillary thyroid carcinoma. This study aimed to investigate the risk factors for LNM in patients with papillary thyroid carcinoma.Methods: The clinicopathological factors of 417 patients were investigated, and differences according to the presence or absence of LNM were evaluated.Results: LNM was associated with age 10 mm, multiple and bilateral tumors, tumor involving the lower pole or entire lobe, lymphovascular invasion (LVI), perineural invasion (PNI), and extrathyroidal extension (ETE). Univariable and multivariable analyses showed that age 10 mm, LVI, and ETE were related to central LNM. Male sex, tumor size >10 mm, and LVI were correlated with lateral LNM (p10 mm, and LVI were risk factors for lateral LNM. ENE was more commonly observed in lateral LNM, and tumor size >10 mm, multifocal tumors, PNI, ETE, and tumors unrelated to lymphocytic thyroiditis were risk factors for ENE.