Bethesda Category | Histopathology subtype | Number of cases | True/False diagnosis | Risk of malignancy % |
Category 1 Inadequate for diagnosis, unsatisfactory | Hyperplastic nodule | 2 | TN | 17% |
Cystic nodule | 1 | TN | ||
Follicular adenoma | 1 | FN | ||
Hurthle adenoma | 1 | FN | ||
Anaplastic cancer | 1 | FN | ||
Category 2 Benign cytology | Colloid Nodule | 15 | TN | 17% |
Adenomatous nodule | 11 | TN | ||
Hyperplastic nodule | 7 | TN | ||
Cystic nodule | 3 | TN | ||
Toxic adenoma | 2 | TN | ||
Hashimoto’s thyroiditis | 2 | TN | ||
Follicular adenoma | 11 | FN | ||
Hurthle adenoma | 1 | FN | ||
Papillary cancer | 10 | FN | ||
Medullary cancer | 1 | FN | ||
NIFTP | 3 | FN | ||
Category 3 AUS/FLUS | Colloid Nodule | 3 | FP | 50% |
Adenomatous nodule | 1 | FP | ||
Cystic nodule | 1 | FP | ||
Papillary cancer | 5 | TP | ||
Category 4 FN/SFN | Colloid Nodule | 2 | FP | 28% |
Adenomatous nodule | 1 | FP | ||
Hyperplastic nodule | 1 | FP | ||
Toxic adenoma | 1 | FP | ||
Hashimoto’s thyroiditis | 3 | FP | ||
Follicular adenoma | 15 | TP | ||
Hurthle adenoma | 3 | TP | ||
Papillary cancer | 5 | TP | ||
Follicular cancer | 4 | TP | ||
Hurthle cancer | 1 | TP | ||
Lymphoma | 1 | TP | ||
NIFTP | 2 | TP | ||
Category 5 Suspicious for Malignancy | Hyperplastic nodule | 2 | FP | 36% |
Hashimoto’s thyroiditis | 2 | FP | ||
Follicular adenoma | 1 | TP | ||
Hurthle adenoma | 1 | TP | ||
Papillary cancer | 3 | TP | ||
Follicular cancer | 1 | TP | ||
NIFTP | 1 | TP | ||
Category 6 Malignant | Papillary cancer | 3 | TP | 100% |