Predicting malignant involvement in a thyroid nodule: role of ultrasonography.

Objective: To assess how ultrasonography can contribute during the evaluation of a thyroid nodule and whether this technique can have a role in predicting malignant involvement.Methods: In this retrospective study, data were analyzed on 220 consecutive patients (with 348 thyroid nodules) who underwent thyroidectomy and had previously undergone assessment by high-resolution thyroid ultrasonography. Nodule size, echogenicity, regularity of margins, halo sign, presence or absence of calcifications, and invasion of surrounding tissues were evaluated. The nodules were classified as low, medium, or high risk for malignant involvement on the basis of nodule characteristics found on ultrasonography. All nodules were submitted to cytologic examination by fine-needle aspiration (FNA) before thyroidectomy. Ultrasound, FNA, and pathologic postoperative results were compared.Results: Among the 348 thyroid nodules, 56 were ultrasonographically classified as low risk, 268 as medium risk, and 24 as high risk for malignan...