1. Malignancy Risks for Fine-Needle Aspiration of Thyroid Lesions According to The Bethesda System for Reporting Thyroid Cytopathology
Vickie Y. Jo, M.D., Edward B. Stelow, M.D., Krisztina Z. Hanley, M.D.
Department of Pathology, University of Virginia, Charlottesville, VA

2. Background
Fine-needle aspiration is important for triaging patients with thyroid nodules

3. Background 30,000,000 patients with thyroid nodules > 1cm
30,000 malignancies
<2,000 deaths due to thyroid cancer

4. Background No “universal” reporting schema Confusing terminologies
2007: “NCI Thyroid Fine-Needle Aspiration State of the Science Conference”

5. NCI Thyroid FNA “State of the Science”
Six Committees
(1) Indications and pre-FNA requirements (2) Training and credentialing for FNA (3) Technique (4) Reporting terminology and morphologic criteria (5) Ancillary studies (6) Post-FNA testing and treatment

6. NCI Thyroid FNA “State of the Science”
Six Committees
(1) Indications and pre-FNA requirements (2) Training and credentialing for FNA (3) Technique (4) Reporting terminology and morphologic criteria (5) Ancillary studies (6) Post-FNA testing and treatment

7. Bethesda Diagnostic Categories
I. Nondiagnostic / Unsatisfactory
II. Benign
III. Atypia of Undetermined Significance / Follicular Neoplasm of Undetermined Significance
IV. Suspicious for Follicular Neoplasm / Follicular Neoplasm
V. Suspicious for Malignancy
VI. Malignant

8. The Bethesda System for Reporting Thyroid Cytopathology
Diagnostic Category
Risk of Malignancy
Usual Management
Nondiagnostic
Repeat FNA with u/s
Benign
0-3%
Clinical follow-up
Atypical Follicular Lesion of Undetermined Significance
5-15%
Repeat FNA
Suspicious for Follicular Neoplasm
15-30%
Surgical lobectomy
Suspicious for Malignancy
60-75%
Near-total thyroidectomy or surgical lobectomy
Malignant
97-99%
Near-total thyroidectomy

9. Aim of Study
What is our institution’s experience with the proposed nomenclature?

10. Methods
Reviewed all thyroid FNA diagnoses at the University of Virginia
Recorded interpretations using new terminology
Recorded follow-up cytology and histology

11. Methods: Examples BENIGN SUSPICIOUS FOR FOLLICULAR NEOPLASM
Thyroid, Right Lobe, FNA: Abundant hemosiderin-laden macrophages, scant benign follicular cells, some colloid and rare Hürthle cells consistent with hemorrhagic cyst.
BENIGN
Thyroid, Right Lobe, FNA: Cellular follicular lesion.
SUSPICIOUS FOR FOLLICULAR NEOPLASM

12. Methods “Cyst-fluid-only” was considered non-diagnostic
“Atypical Follicular Lesion of Undetermined Significance”
Aspirate considered adequate
Diagnosis and/or note suggested the best course of action was re-aspiration

13. Methods Incidental papillary carcinomas were not considered malignant
Malignant follow-up rate was calculated using only surgical resection cases
Except Benign - calculation used total number of FNAs as the denominator

14. Methods We look at Romanowsky- and Papanicolaou-stained slides
Occasionally Thin-Prep (usually cysts)
We only use “rapid” interpretation with a fraction of cases

15. Results Bethesda Diagnosis No. Cases (%) Nondiagnostic 574 (19%)
3080 Thyroid FNAs
Bethesda Diagnosis
No. Cases (%)
Nondiagnostic
574 (19%)
Benign
1817 (59%)
AFLUS
104 (3%)
SFN
298 (10%)
Suspicious for Malignancy
71 (2%)
Malignant
216 (7%)

16. 908 cases with follow-up surgical pathology
Rates of Malignancy
908 cases with follow-up surgical pathology
Bethesda Category
Rate of Malignancy
Reported Rates
Nondiagnostic
13%
Benign
1.6%
0-3%
AFLUS
19%
5-15%
SFN
25%
15-30%
Suspicious for Malignancy
70%
60-75%
Malignant
98%
97-99%

17. Results 126 ND cases were cyst-fluid-only
137 follow-up cytology cases for those originally interpreted as ND
64 (47%) of these remained ND

18. Conclusions
At our institution, Bethesda classification of thyroid lesions yields similar results for risk of malignancy
The associated risks of AFLUS, SFN, and suspicious for malignancy confirm the importance of these categories

19. Limitations Retrospective study
We did not review aspirate slides but used a “best fit” philosophy
Tertiary care center for thyroid malignancy

20. Thank You Edward B. Stelow, M.D. Krisztina Z. Hanley, M.D.
Simone M. Dustin, M.D.
James N. Lampros, M.D.