Fine-needle aspiration biopsy versus frozen section examination in assessing cervical lymph node metastasis in primary clinically positive neck papillary thyroid carcinoma

Background Both fine-needle aspiration biopsy (FNAB) and frozen section (FS) examination are reliable methods for assessing cervical lymph node (level II-V) metastasis (LNM) in papillary thyroid carcinoma (PTC). Our goal was to compare the diagnostic accuracy of FNAB and FS in clinically positive neck (cN+) PTC patients. Methods Altogether, 264 lymph node samples from 220 patients were prospectively enrolled. Samples were assessed by FNAB cytology (FNAB-C), thyroglobulin (Tg) FNAB needle wash testing (FNAB-Tg), and FS simultaneously. Diagnostic performance of the different methods were analyzed by the Chi-square test. Results The sensitivity and specificity of FNAB-C alone in predicting LNM was 87.4% and 85.7%, respectively. Combined with FNAB-Tg, the sensitivity and specificity of FNAB-C increased to 98.9% and 81.6%, respectively. The sensitivity and specificity of FS in predicting LNM was 92.4% and 81.1%, respectively. FNAB-C and FNAB-Tg had better sensitivity than FS when applied to solid lymph nodes, and comparable sensitivity when applied to cystic and cystic-solid lymph nodes. Conclusion The utilization of FNAB-Tg significantly improved the diagnostic ability of FNAB-C. FS can be replaced by preoperative FNAB combined with FNAB-Tg without compromising diagnostic accuracy.