Role of ultrasonography in predicting malignancy in patients with thyroid nodules.

The use of ultrasonography (USG) has become an essential part of endocrine surgical practice. We evaluated the value of USG in predicting malignancy of thyroid nodules. The accuracy of USG in 857 patients who underwent fine-needle aspiration (FNA) with or without surgery was analyzed in a prospective setting. The diagnostic accuracy of USG was compared to that of FNA and of combined models in 153 operated patients. The malignancy-predicting value of USG in follicular neoplasms and its relation to nodule size were also investigated. Sensitivity, specificity, and overall accuracy (OA) of USG were 84.9%, 95.5%, and 93.7%, respectively. In operated patients, USG had accuracy comparable to that of FNA and combined models (sensitivity 93.3%, specificity 90.6%, OA 92.0%) regardless of nodule size but showed a significant rate of indeterminate results (29.4%). For follicular neoplasms, the sensitivity, specificity, and OA of USG were 100%, 95.4%, and 96.1%, respectively, with indeterminate results for three malignant nodules (42.8%). This acceptable malignancy-predicting value of USG in thyroid nodules supports the potential role of USG for predicting malignancy in selected patients with thyroid nodules. However, the high rate of indeterminate results precludes it from being a standard independent diagnostic method for the present time.