Risk Stratification of Bethesda III Category Thyroid Nodules

Abstract

Background: Atypia of undetermined significance/follicular lesion of undetermined significance (AUS/FLUS) carries a malignancy risk reaching up to 50%. Based on the reported malignancy rate in a given population, the clinical practice towards such a category varies. We hereby identify clinical parameters for risk stratification to aid in decision making for either surgical referral or a clinical follow-up. Our aim is to calculate the malignancy risk in Bethesda category III and to identify clinical parameters that guided both clinicians and patients at our institutions to reach a clinical decision.

Methods: A retrospective review of patients with Bethesda category III thyroid nodules from the tertiary centers in the Emirate of Abu Dhabi during January 2011 through December 2015 was carried out. Malignancy risk in Bethesda category III nodules and repeat fine-needle aspiration (FNA) utility were calculated. Parameters guided referral to surgery were studied.

Results: A total of 202 cases were included in the study. Of these, 101 cases underwent surgery initially following the first FNA, and 10 cases following repeat FNA. Histology confirmed malignancy in 41% of cases that went initially to surgery, and in 40% of cases that underwent a repeat FNA. Repeat FNA resulted in 17 (44.74%) cases being re-classified into benign category, 10 (26.3%) being AUS/FLUS category, six (15.7%) being both suspicious and malignant, and five (13.16%) being unsatisfactory. Repeating FNA resulted in a definitive diagnostic utility in 50% of the cases.

Conclusions: The relatively high malignancy rate in our institutions, the suspicious radiographic features and the repeat FNA predictive value stratified Bethesda category III nodules for appropriate referrals to surgery.




J Endocrinol Metab. 2019;9(6):180-185
doi: https://doi.org/10.14740/jem625