Prognostic role of the Bethesda System for conventional papillary thyroid carcinoma

Abstract

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.