A New Marker for Diagnosis of Thyroid Papillary Cancer

Objective. The purpose of this study was to correlate the presence and patterns of distribution of Bflow imaging (BFI) twinkling signs within thyroid nodules with the histologic evidence of microcalcifications and the results of the sonographically guided fine-needle aspiration to establish their role in predicting the risk of malignancy. Methods. Between September 2006 and December 2007, 343 consecutive patients with 479 suspected nodules (maximum diameter >9 mm) were enrolled in this prospective study. Sonographic and BFI examinations were performed with a commercially available real-time sonography system, and all patients also underwent a cytologic evaluation. Written informed consent was obtained from all patients. Patients with suspicious or malignant cytologic features underwent surgery. Results. On histologic examination, 66 of 479 nodules were malignant (59 papillary thyroid carcinoma, 1 Hurthle cell carcinoma, and 6 follicular carcinoma). All sonographic characteristics, which were potential predictors of thyroid malignancy (microcalcifications, hypoechogenicity, absence of a halo, and a predominantly solid composition), were found in different percentages in both histologically verified malignant and benign nodules. For BFI, pattern 3 (≥4 signs and distance >2 mm) was the most predictive factor for malignancy (specificity, 99.6%; sensitivity, 65.2%), whereas pattern 2 (≥4 signs and distance <2 mm) was a positive factor because it was detected only in benign lesions, with a positive predictive of 0. Conclusions. Our results indicate that BFI can overcome the limits of the traditional B-mode and color Doppler sonographic features in the diagnosis of thyroid nodules. This technique provides maximum specificity levels both in the case of benign nodules with pattern 2 and in the case of malignant nodules with pattern 3. Key words: B-flow twinkling sign; papillary cancer; psammoma body; sonography; thyroid nodule.