## 3 Results  
Of all 612 patients operated on for benign thyroid diseases, the pathological examination after paraffin embedding diagnosed PTMC in 144 cases (23.52%); 117 (81.2%) patients were female and 27 (18.8%) were male. With an overall mean age of 54.77 \(\pm\) 11.9 years, 79 patients (54.9%) were older than 55 years (mean age 63.65 years) and 65 (45.1%) were less than 55 years old, ranging from 25 to 54 years with a mean age of 43.67 years. The overall mean diameter of tumors was 3.04 \(\pm\) 2.2 mm, and 109 patients (75.7%) had small tumors (less than 5 mm at their largest diameter). Fifty-one patients (35.4%) were diagnosed with multifocal tumors. Regarding pathological type, 110 tumors (76.4%) were the follicular variant, 19 (13.2%) were conventional, and 15 patients (10.4%) were diagnosed with other variants of PTMC, as follows: 10 cases of tall cell variant (6.94%), 3 cases of hobnail PTMC (2.08%), and 2 cases of columnar PTMC (1.38%). The underlying diseases for which the patients were referred to surgical treatment were: multinodular goiter in 106 (73.6%) cases, adenoma in 36 (25%) cases, 25 cases of Hashimoto thyroiditis (17.4%), Basedow's disease and other types of hyperthyroidism in 7 cases (4.9%), and primary hyperparathyroidism in 11 cases (7.6%), with a small percentage presenting a combination thereof. When assessing the histopathologic factors of aggressiveness, the final reports showed that 14.6% of PTMC had extracapsular invasion (21 cases), 5.6% (8 cases) presented perineural invasion, and only 1 case (0.7%) had vascular invasion. Lymphatic emboli were found in 13 patients (9%) and lymph node metastasis in 8 patients (5.6%). The main characteristics of the patients with PTMC in our study are shown in Table 1.  
The mortality rate after surgical treatment was zero; one permanent unilateral paresis (0.69%) and four (2.7%) transitory pareses of the recurrent laryngeal nerve were recorded. One (0.69%) case of permanent hypocalcemia and six (4.1%) cases of transitory hypocalcemia were noted. Considering the ATA risk stratification, most of the patients (112 cases, 77.7%) were included in the low risk category, whereas 32 patients (22.2%) had intermediate risk and no patient met the criteria for the high risk category. We used the Pearson coefficient to find the correlations between positive lymph nodes, as the dependent variable, and other histopathological markers of aggressiveness. No relation with the patients' age and sex was found, but the presence of metastatic lymph nodes was positively correlated with extracapsular invasion (moderate to strong correlation, \(r=0.587\), \(p<0.001\)), lymphatic emboli (moderate to strong correlation, \(r=0.558\), \(p<0.001\)), and perineural invasion (strong correlation, \(r=0.603\), \(p<0.001\)). Moreover, extracapsular invasion was positively correlated with the presence of lymphatic emboli (moderate correlation, \(r=0.488\), \(p<0.001\)), perineural invasion (moderate correlation, \(r=0.501\), \(p<0.001\)), and vascular invasion (weak correlation, \(r=0.2\), \(p=0.01\)). It was also positively correlated (moderate correlation, \(r=0.45\), \(p<0.001\)) with tumors larger than 5 mm and with total diameter when the tumors were multicentric (weak correlation, \(r=0.33\), \(p<0.001\)). The presence of lymphatic emboli was also positively correlated with large tumors (moderate correlation, \(r=0.453\), \(p<0.001\)) and with total diameter in cases of multicentric tumors (\(r=0.406\), \(p<0.001\)) and negatively with small tumors (moderate correlation, \(r=-0.443\), \(p<0.001\)) (Table 2). Positive lymph nodes correlated positively with large tumors (weak to moderate correlation, \(r=0.365\), \(p<0.01\)), but not with the type of disease for which the patient was initially operated on