Tumor multifocality is not an unusual finding in papillary thyroid carcinoma (PTC), but its clinical significance is controversial. In this study, we aimed to evaluate impact of multifocality, tumor number, and total tumor diameter on clinicopathological features of PTC. Medical records of 912 patients who underwent thyroidectomy and diagnosed with PTC were reviewed retrospectively. Patients were grouped into four according to number of tumoral foci: N1 (1 focus), N2 (2 foci), N3 (3 foci), and N4 (≥4 foci). The diameter of the largest tumor was considered the primary tumor diameter (PTD), and total tumor diameter (TTD) was calculated as the sum of the maximal diameter of each lesion in multicentric tumors. Patients were further classified into subgroups according to PTD and TTD. Multifocal PTC was found in 308 (33.8 %) patients. Capsular invasion, extrathyroidal extension, and lymph node metastasis were significantly higher in patients with multifocal tumors compared to patients with unifocal PTC. As the number of tumor increased, extrathyroidal extension and lymph node metastasis also increased (p = 0.034 and p = 0.004, respectively). The risk of lymph node metastasis was 2.287 (OR = 2.287, p = 0.036) times higher in N3 and 3.449 (OR = 3.449, p = 0.001) times higher in N4 compared to N1. Capsular invasion, extrathyroidal extension, and lymph node metastasis were significantly higher in multifocal patients with PTD ≤10 mm and TTD >10 mm than unifocal patients with tumor diameter ≤10 mm (p < 0.001, p < 0.001 and p = 0.001, respectively). There was no significant difference in terms of these parameters in multifocal patients with PTD ≤10 mm and TTD >10 mm and unifocal patients with tumor diameter >10 mm. In this study, increased tumor number was associated with higher rates of capsular invasion, extrathyroidal extension, and lymph node metastasis. In a patient with multifocal papillary microcarcinoma, TTD >10 mm confers a similar risk of aggressive histopathological behavior with unifocal PTC greater than 10 mm.

US-guided PLA is a new, successful treatment method which is reliable in the long term in benign solid thyroid nodules for selected patients who are inoperable or do not prefer surgery.

Elastosonography (ES) is a newly developed method that is used for the differential diagnosis of benign and malignant thyroid nodules. In different studies, ES scoring has been compared with histopathological findings, and sensitivity and specificity of the scoring were calculated. In this study, it determines the strain index (SI) as well as the ES to score thyroid nodules, and establishes the role for these parameters in the differential diagnosis of thyroid nodules using histopathological analysis as a reference standard. Real-time ES in transverse axis (TA) and longitudinal axis (LA) was performed in 391 nodules of 292 patients. ES scoring was made for all the nodules. SI in TA and LA was calculated for four times in each nodule and mean values were determined. The results were compared with final histopathological diagnoses. In histopathological examinations, 125 (31.97%) of 391 nodules were malignant and 266 (68.03%) were benign. Of these histopathologically benign nodules, 189 (%71.05) were also probably benign according to elastosonographic scoring (scores of 1, 2, or 3), while 77 (28.95%) were probably malignant (scores of 4 or 5). Among 125 histopathologically malignant nodules, 52 (41.60%) were probably benign and 73 (58.40%) were probably malignant according to elastosonographic scoring. There was a significant relation between scoring and histopathological findings (χ(2) = 36.513; P < 0.001). Accordingly, sensitivity and specificity of ES scoring were 58.4 and 71.0%, respectively. ROC analysis value obtained for strain ratios in LA (AUC: 75.5%; P < 0.001) had a higher significance compared to ROC analysis value obtained for strain ratios in TA (AUC: 66.0%). Thus, ROC analysis evaluation was applied only for SI in LA. The optimal SI cut-off value in LA for all the nodules was found to be 16.709 (sensitivity: 73.4%, specificity: 70.0%) (AUC: 75.4 ± 0.03%; 70.2-80.5%). SI cut-off value corresponding to 90% sensitivity in this axis was 4.516 (specificity: 35.7%). Sensitivity and specificity of SI values that were determined according to morphological features of nodules in gray-scale ultrasonography were higher. For hypoechoic nodules with microcalcifications and without a halo, SI cut-off value, sensitivity, and specificity were 17.020, 84.3, and 81.1%, respectively. Our study is the first clinical-wide series study that measured, used, and compared the ES scoring and SI cut-off values for the differential diagnosis of benign and malignant thyroid nodules. This study indicates that measurement of SI with ES as a noninvasive procedure may be used as an adjunctive method to the conventional methods for the differential diagnosis of thyroid nodules.

No abstract

TIRADS seems to be useful in predicting malignancy and planning further management in the AUS subcategory, but not quite so in the FLUS subcategory.