Preoperative ultrasonographic tumor characteristics as a predictive factor of tumor stage in papillary thyroid carcinoma

BACKGROUND: The purpose of this study was to evaluate the usefulness of tumor characteristics on ultrasonography for predicting the pathologic stage of papillary thyroid carcinoma. METHODS: We evaluated 354 patients who underwent surgery for papillary thyroid carcinoma (≤2 cm). We analyzed the preoperative ultrasonography findings such as tumor size, shape, margin, echogenicity, calcification, vascularity, and contact with the capsule. RESULTS: Tumor size, echogenicity, and contact with the capsule were predictive for the presence of extrathyroid extension. Size and echogenicity were significantly associated with central lymph node metastasis in the multivariate analysis. Some ultrasonography characteristics such as round shape, well-defined margin, and isoechoic echogenicity were negative predictive factors for extrathyroid extension and central lymph node metastasis. CONCLUSION: Preoperative tumor characteristics on ultrasonography correlated with several prognostic factors for papillary thyroid carcinoma and may serve as preoperative supplementary markers for determining the optimal extent of surgery.