[Ultrasonic diagnosis of cold thyroid nodules].

Ultrasonographic examination was carried out in 90 patients in whom single thyroid nodule was found by palpation and scintigraphic examination. In 67 of these patients (61%) the presence of a single nodule was confirmed by ultrasonography. In the remaining 23 (38%) multiple nodules were found within the gland. Ultrasonographic examination made possible the differentiation of solid lesions from the cystoid ones in 100%. Follicular adenomas appeared in ultrasonography as mixed-type nodules with the features of degeneration characterized by the presence of the areola (the so called "halo"). The Hurtle's adenomas appeared as mixed-type nodules, hypo-echogenic and devoid of areola. The observed neoplastic lesion (carcinoma follicular) was of a cystoid type. The appearance of cystoid lesions made possible the differentiation of simple cysts from those originating from tumor decomposition. Ultrasonography may then be helpful not only for distinguishing between cystoid-type and solid type lesions but also for classifying solid nodular structures as malignant or benign.