Investigation of correlation between cytological and histological findings in suspected carcinoma of thyroid

ABSTRACT Introduction: The thyroid cytopathologic classification based on The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) standardized results derived from fine-needle aspiration (FNA). It has facilitated communication among clinicians, seems to reduce the number of unnecessary thyroidectomies and also improves the quality of malignancy detection. Objective: To evaluate the correlation between cytopathological samples classified according to TBSRTC and their histological finding after specimen examination following surgical procedure. Methods: Cytopathological samples classified according to TBSRTC were correlated with the respective anatomopathological finding after thyroidectomy. There were retrospectively included all cases of thyroidectomy with previous FNA in the same lateral position of the organ that occurred within two years. Results: The 200 cases of thyroid FNA analyzed were distributed in 25 nondiagnostic or unsatisfactory cases (I; 12.5%), 45 benign cases (II; 22.5%), 48 atypia or follicular lesions of undetermined significance [(AUS/FLUS), III; 24%], 23 suspected cases for follicular neoplasia or follicular neoplasias [(SFN/FN), IV; 11.5%], 40 cases suspected for malignancy (V; 20%), and 19 malignant cases (VI; 9.5%). The malignancy rates observed for categories I to VI were 12%, 13.3%, 29.2%, 43.5%, 85%, and 100%, respectively. Conclusion: The prevalence of Bethesda II category was lower than predicted by TBSRTC (60%-70%), as well as Bethesda III was higher than recommended (7%). Nevertheless, the corresponding malignancy rates were within the expected ranges.