Table 4.
Histopathologic Findings of Only Classic Papillary Thyroid Carcinomas and Follicular Variant of Papillary Thyroid Carcinomas
| Classic PTC | fvPTC | |||||
|---|---|---|---|---|---|---|
| III and IV (n=14) | V and VI (n=191) | p-value | III and IV (n=38) | V and VI (n=34) | p-value | |
| Tumor size (cm)1 | 0.9 (0.5–3.0) | 1.2 (0.2–11.0) | 0.144 | 1.5 (0.7–7.5) | 1.3 (0.4–10.0) | 0.523 |
| Extrathyroidal extension | 4 (29%) | 57 (30%) | 0.920 | 5 (13%) | 8 (24%) | 0.253 |
| Lymphovascular invasion | 2 (14%) | 23 (12%) | 0.804 | 3 (8%) | 5 (15%) | 0.359 |
| Multifocal | 5 (36%) | 92 (48%) | 0.368 | 15 (40%) | 20 (59%) | 0.101 |
| Positive margins | 1 (7%) | 19 (10%) | 0.733 | 2 (5%) | 2 (6%) | 0.909 |
| Suspicious lymph nodes (only if CND performed) | 1 (33%) | 22 (13%) | 0.350 | 3 (50%) | 5 (21%) | 0.300 |
| Lymph node metastases2 | 3 (50%) | 88 (50%) | 0.989 | 6 (46%) | 11 (41%) | 0.746 |
| % Positive Lymph nodes | 6/33 (18%) | 378/1515 (25%) | 0.568 | 9/48 (19%) | 37/234 (16%) | 0.737 |
| # lymph nodes sampled1 | 0 (0–14) | 7 (0–33) | <0.001 | 0 (0–13) | 6 (0–18) | <0.001 |
| Extranodal ext.3 | 1 (33%) | 9 (10%) | 0.208 | 2 (33%) | 2 (18%) | 0.584 |
| % Radioactive Iodine | 8 (57%) | 131 (69%) | 0.376 | 21 (55%) | 23 (68%) | 0.282 |
| Radioactive iodine dose | 49 (0–152) | 53 (0–353) | 0.181 | 51 (0–446) | 75 (0–293) | 0.091 |
| Length of followup | 13.5 (2–78) | 21 (0–105) | 0.334 | 20 (0.5–97) | 13 (0.3–104 | 0.446 |
| Recurrence | 1 (7%) | 14 (7%) | 0.979 | 0 (0%) | 1 (3%) | 0.465 |
| Time to recurrence | 24 (24–24) | 11.5 (0–60) | 0.352 | n/a | 23 (23–23) | n/a |
| Overall survival | 100% | 100% | 1.000 | 100% | 100% | 1.000 |
1
Median (range).
2
Percentages reflect only patients who had lymph nodes sampled.
3
Percentages restricted to only tumors with positive lymph nodes.
PTC=papillary thyroid carcinoma, fvPTC=follicular variant of papillary thyroid carcinoma. CND = central compartment lymph node dissection.