Table 8.
The Bethesda System for Reporting Thyroid Cytopathology: Diagnostic Categories and Risk of Malignancya
| Diagnostic category | Estimated/predicted risk of malignancy by the Bethesda system, %a | Actual risk of malignancy in nodules surgically excised, % median (range)b |
|---|---|---|
| Nondiagnostic or unsatisfactory | 1–4 | 20 (9–32) |
| Benign | 0–3 | 2.5 (1–10) |
| Atypia of undetermined significance or follicular lesion of undetermined significance | 5–15 | 14 (6–48) |
| Follicular neoplasm or suspicious for a follicular neoplasm | 15–30 | 25 (14–34) |
| Suspicious for malignancy | 60–75 | 70 (53–97) |
| Malignant | 97–99 | 99 (94–100) |
a
As reported in The Bethesda System by Cibas and Ali (1076).
b
Based on the meta-analysis of eight studies reported by Bongiovanni et al. (103). The risk was calculated based on the portion of nodules in each diagnostic category that underwent surgical excision and likely is not representative of the entire population, particularly of nondiagnostic and benign diagnostic categories.