Examining the Bethesda criteria risk stratification of thyroid nodules

Ahmed Deniwar; Catherine Hambleton; Tina Thethi; Krzysztof Moroz; Emad Kandil

doi:10.1016/j.prp.2015.02.005

Examining the Bethesda criteria risk stratification of thyroid nodules

Pathol Res Pract. 2015 May;211(5):345-8. doi: 10.1016/j.prp.2015.02.005. Epub 2015 Feb 27.

Authors

Ahmed Deniwar¹, Catherine Hambleton², Tina Thethi³, Krzysztof Moroz⁴, Emad Kandil⁵

Affiliations

¹ Division of Endocrine and Oncologic Surgery, Department of Surgery, Tulane University School of Medicine, New Orleans, LA, United States. Electronic address: adeniwar@tulane.edu.
² Division of Endocrine and Oncologic Surgery, Department of Surgery, Tulane University School of Medicine, New Orleans, LA, United States. Electronic address: chamblet@tulane.edu.
³ Division of Endocrinology and Metabolism, Department of Medicine, Tulane University School of Medicine, New Orleans, LA, United States. Electronic address: tthethi@tulane.edu.
⁴ Department of Pathology, Tulane University School of Medicine, New Orleans, LA, United States. Electronic address: kmoroz@tulane.edu.
⁵ Division of Endocrine and Oncologic Surgery, Department of Surgery, Tulane University School of Medicine, New Orleans, LA, United States. Electronic address: ekandil@tulane.edu.

PMID: 25796296
DOI: 10.1016/j.prp.2015.02.005

Abstract

Background: The Bethesda criteria are proposed for appropriate stratification of malignancy risk in thyroid nodules, but controversy exists regarding their accuracy and reliability in decision making. Additionally, previous studies have suggested higher rates of both malignancy and false negative fine needle aspiration biopsy (FNA) associated with increasing nodule size. This study aims to determine the accuracy of ultrasound (US)-guided FNA using the current Bethesda criteria in surgical practice. We also aimed to investigate the relationship between nodule size and malignancy.

Methods: A retrospective analysis of US-guided FNAs by a single surgeon during a 4.5 year period. FNA results using Bethesda criteria were compared to final surgical pathology.

Results: 611 patients with thyroid nodules underwent US-guided FNA. FNA results in 375 subsequently excised thyroid nodules were recorded according to the Bethesda criteria: 192 (51%) benign, 65 (17%) atypia of unknown significance/follicular lesion of undetermined significance (AUS/FLUS), 42 (11%), suspicious for follicular neoplasm (SFN), 17 (5%) suspicious for malignancy (SM), 28 (8%) malignancy, and 31 (8%) non-diagnostic. Malignancy was confirmed by surgical pathology in 15%, 34%, 50%, 88%, 100%, and 39% of the above groups respectively. Sensitivity, specificity, and false-negative rate were 61%, 99%, and 15% respectively. No correlation existed between the size of nodules with indeterminate FNA results and malignancy rate (p=0.89), or size of nodules with non-diagnostic FNA and malignancy rate (p=0.50).

Conclusion: The current Bethesda risk stratification system underestimated malignancy rates in benign, indeterminate and non-diagnostic cytopathologic categories in our experience. There was no positive linear correlation between nodule size and malignancy rate in these cytopathologic categories.

Keywords: Thyroid cancer; Thyroid cytology/FNA; Thyroid nodule evaluation; Thyroid pathology; Thyroid surgery.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Biopsy, Fine-Needle
False Negative Reactions
False Positive Reactions
Female
Humans
Male
Middle Aged
Retrospective Studies
Risk Factors
Sensitivity and Specificity
Thyroid Neoplasms / diagnosis*
Thyroid Neoplasms / epidemiology
Thyroid Nodule / pathology*