Table 2.
Summary of cytological classification based on fine-needle aspiration and rates of malignancy.
| Characteristic | Thy classification | |||||
| 1 | 2 | 3a | 3f | 4 | 5 | |
| Thyroid nodules, n (malignant, n) | 16 (0) | 74 (4) | 52 (8) | 35 (8) | 1 (1) | 9 (9) |
| Rate of malignant neoplasm (%) | 0 | 5.4 | 15.4 | 22.8 | 100 | 100 |
| Pathology of malignant nodules, (n): | ||||||
| Papillary thyroid cancer (PTC) | 0 | 3 | 3 | 2 | 0 | 9 |
| PTC follicular variant | 0 | 1 | 2 | 3 | 1 | 0 |
| Follicular thyroid cancer (FTC) | 0 | 0 | 2 | 2 | 0 | 0 |
| FTC, Hürtle cell variant | 0 | 0 | 0 | 1 | 0 | 0 |
| Medullary thyroid cancer | 0 | 0 | 1 | 0 | 0 | 0 |