Prognostic role of the Bethesda System for conventional papillary thyroid carcinoma.

BACKGROUND The purpose of this study was to investigate the role of the Bethesda System for Reporting Thyroid Cytopathology (BSRTC) as a prognostic marker in conventional papillary thyroid carcinoma (PTC). METHODS A total of 397 patients who underwent ultrasound-guided fine-needle aspiration biopsy (FNAB) and surgery for conventional PTCs were enrolled. The association between the Bethesda category and histopathologic result was evaluated. RESULTS Among the Bethesda categories, a significant difference was found in the presence of extrathyroidal extension (Bethesda category III, 3.2% [7 of 220]; category V, 19.1% [42 of 220]; and category VI, 77.7% [171 of 220]; p < .001) and lymph node metastasis (Bethesda category III, 3.8% [6 of 156]; category V, 16.7% [26 of 156]; and category VI, 79.5% [124 of 156]; p < .001). Multivariate analysis showed that the Bethesda category was independently predictive of extrathyroidal extension (p = .013) and lymph node metastasis (p = .035). CONCLUSION Conventional PTC with a higher Bethesda category at the time of cytology diagnosis would be poor prognosis. © 2016 Wiley Periodicals, Inc. Head Neck 38: First-1514, 2016.