Malignant thyroid nodules: comparison between color Doppler diagnosis and histological examination of surgical samples.

The aim of this study was to verify the reliability of the differential diagnosis between benign and malignant thyroid nodules on the basis of vascularization. The study was conducted on 108 patients with a scintigraphically "cold" thyroid nodule, including 54 carcinomas and 54 benign nodules. All patients underwent total thyroidectomy. Diagnosis based on histological examination of the surgical specimen was compared with ultrasonographic diagnosis obtained according to a personal classification proposed by the authors. Vascular ultrasonographic investigation produced 10 false positives, 6 false negatives and 92 correct diagnoses, with 88.8% sensitivity, 81.5% specificity, an 82.7% positive predictive value and an 88% negative predictive value. It can thus be used effectively to identify the larger nodules, while it is unable to provide any indication as to their histological type. Ultrasound vascular thyroid study is a non-invasive and low-cost method and is very reliable in the differential diagnosis of cold thyroid nodules. The best ultrasonographic modality is power Doppler. Ultrasound contrast media increase vascular definition but, due to their higher cost and the longhier duration of the examination, they should only be used in the case of small nodules.