B-Flow Twinkling Sign in Preoperative Evaluation of Cervical Lymph Nodes in Patients with Papillary Thyroid Carcinoma

Papillary thyroid cancer (PTC) is the most common histologic type of differentiated thyroid cancer. The first site of metastasis is the cervical lymph nodes (LNs). The ultrasonography (US) is the best diagnostic method for the detection of cervical metastatic LNs. We use a new technique, B-flow imaging (BFI), recently used for evaluation of thyroid nodules, to estimate the presence of BFI twinkling signs (BFI-TS), within metastatic LNs in patients with PTC. Two hundred and fifty-two patients with known PTC were examined for preoperative evaluation with conventional US and BFI. Only 83 with at least one metastatic LN were included. All patients included underwent surgery; the final diagnosis was based on the results of histology. The following LN characteristics were evaluated: shape, abnormal echogenicity, absent hilum, calcifications, cystic appearance, peripheral vascularization, and BFI-TS. A total of 604 LNs were analyzed. Of these, 298 were metastatic, according to histopathology. The BFI-TS showed high values​​of specificity (99.7%) and sensitivity (80.9%). The combination of each conventional US sign with the BF-TS increases the specificity. Our findings suggest that BFI can be helpful in the selection of suspicious neck LNs that should be examined at cytologic examination for accurate preoperative staging and individual therapy selection.

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

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.