Real-time ultrasonography of thyroid nodules.

Sonographic characteristics were analyzed in 141 histologically confirmed thyroid nodules including 84 benign and 57 malignant tumors. Seven items were examined: Presence of a 'halo'; presence of cystic components; presence of calcification; hypoechogenicity; heterogeneity of the internal echo pattern: irregular or obscured margin; and massive extrathyroidal extension. Only the last-mentioned item appeared exclusively, but not very often, in malignant lesions, and the other characteristics were encountered in both benign and malignant lesions. Although ultrasonography is a method of choice for the evaluation of thyroid nodules, its ability to distinguish benign from malignant lesions is limited.