The impact of atypia/follicular lesion of undetermined significance on the rate of malignancy in thyroid fine-needle aspiration: Evaluation of the Bethesda System for Reporting Thyroid Cytopathology

doi:10.1016/j.surg.2011.09.006

Surgery

Volume 150, Issue 6, December 2011, Pages 1234-1241

https://doi.org/10.1016/j.surg.2011.09.006 Get rights and content

Background

The Bethesda System for Reporting Thyroid Cytopathology (BSRTC) was developed to refine definitions and improve clinical communication and management. This study evaluates the impact of the BSRTC in a large cohort of patients undergoing thyroidectomy before and after its adoption at a single institution.

Methods

The records from 469 patients in the pre-BSRTC (n = 187) and post-BSRTC (n = 282) periods were reviewed. Cytologic categories in group 1 included nondiagnostic, benign, follicular/Hürthle neoplasm, suspicious for malignancy, and malignant. Atypia/follicular lesion of undetermined significance (AUS/FLUS) was included in group 2. The percentage of each fine-needle aspiration (FNA) category, malignancy rate per category, and rate of AUS/FLUS utilization were calculated.

Results

Group 1 FNA results included 3% (n = 6) nondiagnostic, 48% (n = 89) benign, 17% (n = 32) follicular/Hürthle, 13% (n = 25) suspicious for malignancy, and 19% (n = 35) malignant. Group 2 results included 4% (n = 11) nondiagnostic, 34% (n = 96) benign, 29% (n = 82) AUS/FLUS, 12% (n = 33) follicular/Hürthle, 10% (n = 29) suspicious for malignancy, and 11% (n = 31) malignant. The rate of cancer changed from 25% to 36% for follicular/Hürthle lesions. AUS/FLUS was utilized in 154 of 1095(14%) FNAs reviewed with a malignancy rate of 20%.

Conclusion

The new AUS/FLUS category was used more often than recommended (14%) with a higher than expected rate of malignancy (20%). Rigorous cytopathology to histopathology correlation is needed to accurately reflect the malignancy rates of the different BSRTC categories at each individual institution. Clinical management should be tailored based on such institutional findings.

Section snippets

Methods

The Vanderbilt Institutional Review Board approved a retrospective review of all patients who underwent thyroid operations, of any type, by members of the Division of Surgical Oncology and Endocrine Surgery from July 2007 through October 2010. Vanderbilt’s Division of Anatomic Pathology, which includes cytology, adopted the BSRTC and implemented its terminology in their reports starting February 2009. All FNA biopsies performed/reviewed since the adoption of the BSRTC (n = 1,095) were

Results

A total of 805 patients underwent thyroidectomy (total, partial, or completion) during the study period with 347 (43%) in the pre- and 458 (57%) in the post-BSRTC era. There was no significant difference between periods regarding age of patients or gender distribution (Table I). The majority of patients went to the operating room for benign disease. Overall, the number of patients going to the operating room for indeterminate FNAs increased from 9% to 24%. Fifty-four percent (187/347) of

Discussion

The present study evaluates the rates of malignancy in patients undergoing thyroidectomy and reports on the impact of the BSRTC at a single academic institution. Since adoption of the BSRTC, there has been an increase in the percentage of patients undergoing surgery for “indeterminate” FNA results (AUS/FLUS, follicular/Hürthle neoplasms). Utilization of the AUS/FLUS category has been higher than suggested (14% vs 7%) by the BSRTC with a malignancy rate that is also higher than anticipated (20%

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American Association of Endocrine SurgeonThe impact of atypia/follicular lesion of undetermined significance on the rate of malignancy in thyroid fine-needle aspiration: Evaluation of the Bethesda System for Reporting Thyroid Cytopathology

Background

Methods

Results

Conclusion

Section snippets

Methods

Results

Discussion

Revised American Thyroid Association management guidelines for patients with thyroid nodules and differentiated thyroid cancer

Thyroid

The Bethesda system for reporting thyroid cytopathology

Thyroid

The Bethesda thyroid terminology and progress towards international agreement on thyroid FNA cytology reporting

Cytopathology

Contribution of molecular testing to thyroid fine-needle aspiration cytology of “follicular lesion of undetermined significance/atypia of undetermined significance.”

Cancer Cytopathol

Long-term assessment of a multidisciplinary approach to thyroid nodule diagnostic evaluation

Cancer

Fine-needle aspiration of thyroid nodules: a study of 4703 patients with histologic and clinical correlations

Cancer

American Association of Endocrine Surgeon
The impact of atypia/follicular lesion of undetermined significance on the rate of malignancy in thyroid fine-needle aspiration: Evaluation of the Bethesda System for Reporting Thyroid Cytopathology