Rates of Malignancy by The Bethesda System for Reporting Thyroid Cytopathology Category 3 and Category 4 Thyroid Nodules

Abstract

Aim: The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) is employed to evaluate the cytopathology of thyroid nodules. The nodules reported as categories 3 and 4 constitute risk of malignancy at varying rates. This study aims to document the amount of actual malignancy rates in TBSRTC category 3 and 4 thyroid nodules. Materials and Methods: Patients having thyroid nodules with reported Bethesda category 3 and category 4 results on fine needle aspiration biopsy who subsequently underwent thyroidectomy between January 2013 and December 2018 were retrospectively analyzed. Results: Seventy-two patients and 72 nodules were included in our study. The Bethesda category 3 group consisted of 40 patients and 40 nodules. The histopathologic result was reported as benign in 23 (57,5%) patients and malignant in 17 (42,5%) patients. The Bethesda category 4 group covered the remaining 32 patients and 32 nodules. Histopathologic results were reported as benign in 12 patients (37,5%) and malignant in 20 patients (62,5%). Conclusion: Bethesda category 3 and 4 nodules bear varying rates of malignancy risk, and this rate increases with the presence of additional incidentally detected malignancies.