Table 3.
Comparison of Postsurgical Characteristics by Histologic Laterality
| Characteristic | Total Cohort (n = 18) | Unilateral Disease (n = 13) | Bilateral Disease (n = 5) |
|---|---|---|---|
| AJCC TNM classificationa | |||
| Primary tumor (T) | |||
| T1a | 1 (6%) | 0 | 1 (20%) |
| T1b | 7 (39%) | 5 (39%) | 2 (40%) |
| T2 | 8 (44%) | 7 (54%) | 1 (20%) |
| T3 | 2 (11%) | 1 (8%) | 1 (20%) |
| T4a or T4b | 0 | 0 | 0 |
| Lymph nodes (N) | |||
| NX | 5 (28%) | 4 (31%) | 1 (20%) |
| N0 | 13 (72%) | 9 (69%) | 4 (80%) |
| N1a or N1b | 0 | 0 | 0 |
| Distant metastasis (M) | |||
| MX | 2 (11%) | 2 (15%) | 0 |
| M0 | 15 (83%) | 11 (85%) | 4 (80%) |
| M1b | 1 (6%) | 0 | 1 (20%) |
| Histopathology characteristics (primary tumor) | |||
| Tumor size in largest dimension, median (range), cm | 2.3 (1.1–4.5) | 2.3 (1.3–4.5) | 2.0 (1.1–2.9) |
| Ipsilateral multifocality | 4 (28%) | 0 | 4 (80%) |
| Histopathology | |||
| Uniform histology (follicular architecture only) | 14 (78%) | 10 (76%) | 4 (80%) |
| Mixed histology (follicular + solid/trabecular) | 4 (22%) | 3 (23%) | 1 (20%) |
| Encapsulation | |||
| Complete encapsulation | 14 (78%) | 9 (69%) | 5 (100%) |
| Capsular invasion | 9/14 | 7/9 | 2/5 |
| No capsular invasion | 5/14 | 2/9 | 3/5 |
| Partial encapsulation | 2 (11%) | 2 (15%) | 0 |
| No encapsulation | 2 (11%) | 2 (15%) | 0 |
| Vascular invasion | |||
| Extensive vascular invasion (≥4 vessels) | 2 (11%) | 1 (8%) | 1 (20%) |
| Minimal vascular invasion (<4 vessels) | 4 (22%) | 3 (23%) | 1 (20%) |
| No vascular invasion | 12 (67%) | 9 (69%) | 3 (60%) |
| Mitotic activity | |||
| High | 0 | 0 | 0 |
| Low | 5 (28%) | 4 (31%) | 1 (20%) |
| None | 13 (72%) | 9 (69%) | 4 (80%) |
| ATA pediatric risk category | |||
| Low | 16 (89%) | 13 (100%) | 3 (60%) |
| Intermediate or high | 2 (11%) | 0 | 2 (40%) |
Abbreviation: TNM, tumor node metastasis.
a
AJCC Cancer Staging Manual, 7th edition (2010).
b
One patient had pulmonary metastases detected postoperatively on whole-body scan. This FVPTC was classified as NX because cervical lymph node dissection was not performed with thyroidectomy.