Thyroid B-flow twinkling sign: a new feature of papillary cancer

Abstract

BackgroundMicrocalcifications (aggregated with psammoma bodies), detected by ultrasound (US), are the most specific feature of papillary thyroid cancer (PTC). Using B-flow imaging (BFI), we identified a new sign (the twinkling sign; BFI-TS) in ‘suspect’ PTC nodules, which appeared to be generated by microcalcifications.ObjectiveTo evaluate whether the BFI-TS was predictive of malignancy, we correlated the BFI-TS with the results of fine needle aspiration cytology and histology.DesignCross-sectional cohort study from September 2006 to April 2008.SettingDepartment of Radiology and Endocrinology, University of Naples Federico II, and Department of Endocrinology, Second University of Naples.PatientsA total of 306 consecutive patients with 539 thyroid nodules >8 mm in diameter.Main outcome measureUS and BFI examinations were performed with the Logiq 9 system (General Electric Company, Milan, Italy); all patients underwent cytological examination.ResultsCytology revealed 455 (84.4%) benign nodules and 84 (15.6%) malignant nodules; the latter were confirmed by postsurgical histological examination (76 cases of PTC, 7 follicular carcinoma, and 1 Hürthle cell carcinoma). All suspect nodules, namely, nodules with potential predictors of thyroid malignancy (e.g., microcalcifications and intra-nodal vascularity), were analyzed by cytology or histology (or both). Of 84, 68 (80.9%) of malignant nodules had ≥4 or more BFI-TSs in at least one scan versus only 12 of 455 (2.6%) of benign lesions.ConclusionsOur results indicate that the BFI-TS could be a reliable diagnostic technique in the management of suspect thyroid nodules.