Table 1 Comparison of demographic and clinicopathologic characteristics among benign and malignant lymph nodes in PTC patients

Clinical Characteristic

No. of patients

373 (100.0%)

1292 (100.0%)

Sex

 Male

102 (27.3%)

440 (34.1%)

0.015

 Female

271 (72.7%)

852 (65.9%)

Age, year

 Median (IQR)

43 (33–52)

37 (30–47)

< 0.001^b

 < 55 (year)

318 (85.3%)

1155 (89.4%)

0.027

 ≥ 55 (year)

55 (14.7%)

137 (10.6%)

Hashimoto’s thyroiditis

167 (44.8%)

530 (41.0%)

0.196

TSH (M ± SD, uIU/ml)

2.67 ± 5.50

2.81 ± 5.02

0.666^c

Pathological Characteristic

No. of diagnostic lymph nodes

394 (100.0%)

1411 (100.0%)

Tumor size, mm

 Median (IQR)

11 (8–16)

17 (11–25)

< 0.001^b

 ≤ 10 (mm)

195 (49.5%)

292 (20.7%)

< 0.001

 > 10 (mm)

199 (50.5%)

1119 (79.3%)

Multifocality

52 (13.2%)

271 (19.2%)

0.006

Bilateral tumor

104 (26.4%)

544 (38.6%)

< 0.001

Capsular invasion

174 (44.2%)

938 (66.5%)

< 0.001

Extrathyroidal extension

49 (12.4%)

494 (35.0%)

< 0.001

Contrast-enhanced ultrasound

71 (18.0%)

194 (13.7%)

0.034

Lymph node location

 Level II

17 (4.3%)

125 (8.9%)

< 0.001

 Level III

98 (24.9%)

539 (38.2%)

 Level IV

274 (69.5%)

712 (50.5%)

 Level V

5 (1.3%)

35 (2.5%)