OBJECTIVE: The conflicting results of the Bethesda system for reporting thyroid cytopathology (BSRTC) and B-Raf proto-oncogene ( MATERIAL AND METHODS: The clinical data of patients with thyroid nodules, suspicious of malignancy at ultrasound (US), who underwent US-guided FNAC between December 2020 and March 2023 at our cancer center were reviewed. Patients with an indeterminate diagnosis, that is, conflicting results of the BSRTC and RESULTS: Among the 1,044 eligible patients, 687 underwent surgical treatment. Of the 687 patients, 117 were in Group 1, 14 in Group 2, 394 in Group 3, and 162 in Group 4. Histopathological examination showed that 677 (98.5%) patients had papillary thyroid cancer, including 585 with papillary thyroid microcarcinoma, whereas only 10 (1.5%) had benign nodules. The malignancy rates were 98.3%, 100%, 98.7%, and 98.1% for Groups 1 to 4, respectively. Among the 387 patients in category 4A by the thyroid imaging reporting and data system (TI-RADS 4A) through the US, the malignancy rate was 98.4%, and for the 116 nodules <
5 mm in diameter in the US, the malignancy rate was 99.1%. When combining TI-RADS 4A and a nodule diameter <
5 mm, the malignancy rate was 98.9% (88/89). A total of 179 patients (26.1%) had histopathologically confirmed central cervical lymph node metastasis, and 46 (6.8%) had lateral cervical lymph node metastasis. Two nodules in Group 1, five nodules in Group 3, and three nodules in Group 4 were determined to be benign post-surgery. The benign thyroid nodules included seven dysplastic, one adenomatous, one fibrotic, and one hyperplastic. CONCLUSION: Thyroid nodules, suspicious of malignancy on US, after the combined interpretation of BSRTC and