| Bethesda System |
| Classes |
Description |
Risk of malignancy
(Percentage) |
Usual management |
| I |
Non-diagnostic or Unsatisfactory |
1-4 |
Repeat |
| II |
Benign |
0-3 |
Follow up |
| III |
Follicular Neoplasm or Suspicious for a Follicular Neoplasm |
5-15 |
surgical lobectomy |
| IV |
Atypia of Undetermined Significance or Follicular Lesion of Undetermined Significance |
15-30 |
surgical lobectomy |
| V |
Suspicious for Malignancy |
60-75 |
near-total thyroidectomy or surgical
lobectomy |
| VI |
Malignant |
100 |
near-total thyroidectomy or surgical
lobectomy |
