In Thyroid Cancer Patients, Is Preoperative FNAB-C Reliable for Prediction of Lateral Cervical LN Metastasis?

Abstract

Purpose: The goal of this study was to evaluate the diagnostic accuracy of preoperative fine needle aspiration biopsy cytology (FNAB-C) in predicting lateral lymph node metastasis in papillary thyroid cancer patients. Methods: A total of 592 patients who underwent thyroid cancer surgery and intraoperative lateral cervical LN frozen section or RND, from January 2002 to December 2011, were evaluated retrospectively. Among them, 228 cases had suspicious findings in FNAB-C of lateral nodes. We reviewed their radiological and pathological reports. Results: Intra-operative frozen section examination was performed in 540 cases and RND was performed in 314 cases. This study included 534 women (83.4%) and 106 men (16.6%). Patients’ ranged in age from 9 to 83 years (mean, 45.65 years). FNAB-C was performed in 228 cases. The sensitivity and specificity of FNAB-C was 71.5% and 78.6%, respectively; 35.9% of cases had a false negative result. The combination of FNAB-C and intra-operative frozen section test sensitivity and specificity was 87.2% and 93.6%, respectively. Conclusion: The results for sensitivity in FNAB-C actually appear low, and false negative results were very high. In papillary thyroid cancer in patients with FNAB-C, even if the result is negative, if lymph node metastasis is suspected based on radiologic evidence, frozen section examination should be performed for determination of metastasis.