## 3 Results  
The final evaluation included 64 patients, 52 were females and 12 were males. The mean age in the group was 32.5 years (within 23-56 years old). Consecutive to surgery, the pathology report confirmed the malignancy diagnosis in 16 cases (25%). Papillary carcinoma was found in the majority of these cases (15/16). Follicular carcinoma was diagnosed only in one case (6.25% of the confirmed malignancies). Forty-three of the nodules were classified as certainly benign (67.18 %). About half of them, 21/43 (32.28% of the total examined cases), were follicular adenomas, 8 (12.5%) were hyperplastic nodules, 5 (7.81%) were Hurthle cell adenomas, 2 (3.1%) were granulomatous thyroiditis, and 6 (9.37%) were autoimmune thyroiditis. Five cases (7.81%) were classified as \"follicular neoplasia with uncertain risk\" or \"borderline neoplasia\". This category included three cases described as havingsome invasion of the capsule without involving its entire width, and two cases with tumoral cell islands detected within the capsule, and associated disruption of the collagen matrix. According to current recommendations [31; 32; 33; 34] we considered them as malignant cases because of the suggestion of watchful waiting due to their unclear evolution. The size of the examined nodules ranged within 11.5-32.5 mm with a mean of 14.7 mm. It was observed that benign lesions were bigger compared to the malignant ones (mean diameter of 21.1 mm for benign cases and 12.3 mm for the malignancies). The general characteristics evaluated for each nodule are illustrated in Table 1.  
Considering qualitative SE scores 1 and 2 as predictive for benignity and scores 3 and 4 as suspicious of malignancy, stiffness evaluation identified 42 low-risk lesions (22 corresponding to score 1 and 20 to score 2) and 22 high-risk nodules (12 in score 3 and 10 in score 4). Three of the five cases with a final diagnosis of malignancy that were classified as low risk on elastography assessment were borderline neoplasia--a category which was considered in this study together with the confirmed cancers, given their uncertain evolution. As for stiff lesions, most of the score 4 nodules (80%) and an important proportion of score 3 cases (66.6%) proved malignant. Qualitative SE alone proved to be of good diagnostic value for detecting cancer due to its 76.2% sensitivity, 86% specificity, PPV of 72.7%, NPV of 88.1%, and an accuracy of 82.81% (54/64 cases). Compared to soft nodules, stiff lesions presented a considerably greater risk of malignancy (\(p\) = 0.020). The distribution of cases according to stiffness scores is reported in Table 2. Figure 3 shows that the area under the receiver operating characteristic (ROC) curve was very good for SE-only information (0.83, CI = 0.721-0.916). This outlines the great value that SE brings to the risk assessment, even when considered on its own. \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Characteristic** & **CA** & \multicolumn{2}{c}{**BN**} \\ \hline  & 21 cases & \multicolumn{3}{c}{43 cases} \\ \hline  & No. & \% & No. & \% \\ \hline Intense hypoechoic & 5 & 23.8 & 15 & 34.8 \\ Iso-/hyper-/mild hypoechoic & 16 & 76.1 & 28 & 65.1 \\ Ill-defined margins & 11 & 52.3 & 11 & 25.6 \\ Well-defined margins & 10 & 47.6 & 32 & 74.4 \\ Taller than wide & 11 & 52.4 & 4 & 9.3 \\ Wider than tall & 9 & 42.8 & 39 & 90.6 \\ Inhomogeneity & 16 & 76.2 & 6 & 13.9 \\ Homogeneity & 5 & 23.8 & 37 & 86.1 \\ Intranodular microcalcifications & 17 & 80.9 & 43 & 100 \\ Absent/perinodular calcifications & 4 & 19.1 & 0 & 0 \\ No lymph nodes & 0 & 0 & 43 & 100 \\ Lymph nodes & 7 & 33.4 & 0 & 0 \\ \hline ES 1,2 & 5 & 23.8 & 37 & 86.1 \\ ES 3,4 & 16 & 76.2 & 6 & 13.9 \\ \hline Absent/low vascularization & 6 & 28.5 & 39 & 90.7 \\ Moderate/intense vascularization & 15 & 71.4 & 4 & 9.3 \\ \hline \hline \end{tabular} BN—benign cases; CA—cancer cases; No.—number of cases; %—percentage of cases; ES—elastography score.  
\end{table} 
Table 1: Ultrasound characteristics in each nodule (64 cases).