Preoperative diagnosis of thyroid nodules using the Bethesda System for Reporting Thyroid Cytopathology: a comprehensive review and meta-analysis.

Fine-needle aspiration biopsy (FNAB) is the test of choice for the evaluation of nodules, arriving at a cancer diagnosis, and guiding surgical management. This review and meta-analysis aims to objectively evaluate the Bethesda System for Reporting Thyroid Cytopathology (BSRTC) based upon literature reports of histopathological outcomes following cytopathological diagnoses. Thirteen studies were reviewed and the risk of malignancy (ROM) for each of the BSRTC diagnostic categories were calculated as: Non-diagnostic 11-26%, Benign 4-9%, AUS/FLUS 19-38%, FN/SFN 27-40%, SFM 50-79%, and Malignant 98-100%. In typical clinical utilization, the sensitivity and specificity of thyroid FNAB diagnosis using the BSRTC were 96% and 46%, respectively. The BSRTC represents an important advance in standardizing thyroid FNAB cytopathological reporting. Close attention should be paid to the observation that the AUS-FLUS and FN-SFN DCs have overlapping ROMs, and the potential clinical implications of this finding on patient management.