A new marker for diagnosis of thyroid papillary cancer: B-flow twinkling sign.

OBJECTIVE: The purpose of this study was to correlate the presence and patterns of distribution of B-flow 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 Hürthle 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 (> or = 4 signs and distance > 2 mm) was the most predictive factor for malignancy (specificity, 99.6%; sensitivity, 65.2%), whereas pattern 2 (> or = 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.