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%