Sonographic features of primary tumor as independent predictive factors for lymph node metastasis in papillary thyroid carcinoma.

PURPOSE: The aim of this research was to find the sonographic features of primary tumor as independent predictive factors for lymph node metastasis in papillary thyroid carcinoma.

METHODS/PATIENTS: To facilitate the research, 514 patients with papillary thyroid carcinoma were divided into solitary and multifocal groups. In solitary group, thyroid lesions were divided into several subgroups by size, border, margin, echogenicity, echohomogeneity, calcification, vascularization, location, stiffness and Hashimoto's thyroiditis (HT) conditions. Then, univariable and multivariable analyses were performed to find the sonographic features of primary tumor as independent predictive factors for lymph node metastasis in papillary thyroid carcinoma.

RESULTS: A significant difference of lymph node metastasis rate was found between multifocal and solitary groups (P < 0.05). In univariable analysis, size, vascularization and coexistence of HT were found to be statistically significant factors (P = 0.004, 0.118, 0.016). Multivariable analysis revealed that lymph node metastasis rate was mainly associated with size [odds ratio (OR) = 1.690, 95 % confidence interval (CI) 1.157-2.469] and coexistence of HT (OR = 0.441, 95 % CI 0.219-0.888).

CONCLUSION: Preoperative sonographic features of primary tumor including the number, size and coexistence of HT were independent predictive factors for the state of cervical lymph node metastasis in patients with papillary thyroid carcinoma.