Table 3.
Differences in lymph node metastasis between the different extrathyroid extension groups.
| Characteristic | Total | ETE negative n (%) | ETE positive n (%) | p |
|---|---|---|---|---|
| PTC vs PTMC | ||||
| Group A | 210 | 101 (48.1) | 109 (51.9) | 0.838 |
| Group B | 85 | 42 (49.4) | 43 (50.9) | |
| PTMC | ||||
| Group C | 712 | 530 (74.4) | 182 (25.6) | 0.068 |
| Group D | 211 | 170 (80.6) | 41 (19.4) | |
| Group C | 712 | 530 (74.4) | 182 (25.6) | 0.005 |
| Group E | 179 | 115 (64.2) | 64 (35.8) | |
| Group D | 211 | 170 (80.6) | 41 (19.4) | <0.001 |
| Group E | 179 | 115 (64.2) | 64 (35.8) | |
ETE: extrathyroidal extension; Group A: PTC, unifocal with diameter >1 cm and ≤2 cm; Group B: PTMC multifocal with total tumor diameter (TTD) >1 cm and ≤2 cm; Group C: PTMC unifocal with diameter ≤1 cm; Group D: PTMC multifocal with TTD ≤ 1 cm; Group E: PTMC multifocal with TTD >1 cm.