The Bethesda system for reporting thyroid fine needle aspirates: A study of 1763 patients; with histopathological...

Fine-needle aspiration cytology (FNAC) is an important test for triaging patients with thyroid nodules. The 2007 National Cancer Institute Thyroid Fine-Needle Aspiration State-of-the-Science Conference helped instigate the recent publication of The Bethesda System for Reporting Thyroid Cytopathology (TBS).

Terminology and therefore the probability of malignancy vary between pathologists and institutions. The purpose of this study was to evaluate a single institution's experience to determine if sub-classification (neoplasm versus lesion) aids in identifying patients at higher risk for malignancy. Also, an effort in regional and worldwide variation of significance of adoption of Bethesda classification has been evaluated.

From 2018 to 2021, all patients with thyroid lesions' were evaluated for FNAC correlation with the surgical diagnosis. During this period, 1763 thyroid FNACs were reported. Histopathological examination (HPE) outcome data was available in 444 (25.2%) cases.

The cytologic-histologic diagnostic discrepancy rate was 11.5%. The sensitivity and specificity of thyroid FNA for the diagnosis of malignancy were 71.4% and 49.5%, respectively. In our study, the maximum cases were benign (84.5%). The malignancy risk for the different categories in our study, as seen by follow-up HPE, has corroborated well with the Bethesda System.

The current results indicated that FNAC provides an accurate diagnosis of thyroid malignancy. The classification is directly related to the risk of malignancy in each category and this helps in accurate clinical management of that category.