Comparison of Consecutive Results from Fine Needle Aspiration and Core Needle Biopsy in Thyroid Nodules

There are papers suggesting the complementary role of core needle biopsy (CNB) in the diagnosis of thyroid nodules. By comparing the result of CNB and fine needle aspiration (FNA) cytology performed in consecutive cases of thyroid nodules, the role of CNB was evaluated. Retrospective reviews of 2131 FNA and 275 CNB which were performed as first-line biopsy for 2406 thyroid nodules in 2187 patients were performed. The ultrasound (US) feature of thyroid nodule was classified following the risk of malignancy suggested by American Thyroid Association (ATA) guideline. Rate of unsatisfactory and cellular atypia could be decreased significantly by first-line CNB in all US group, and the nodules with highly suspicious feature showed significant decrease in inconclusive result by first-line CNB. However, increased rates of architectural and follicular neoplasm (FN) were identified in CNB group especially in intermediate and low suspicious nodules, and the first-line CNB could not decrease the inconclusive result in these US groups. The diagnostic rate of neoplasm diagnosed by surgery following the result of architectural atypia or FN was not different between FNA and CNB even with significantly higher rate in CNB group. Furthermore, the sensitivity for follicular neoplasm (21.2 vs. 61.9%) was significantly higher in CNB group. The CNB can be considered in nodules with highly suspicious feature with advantage of significantly lower inconclusive diagnostic rate than FNA group. However, significantly increased diagnosis of architectural atypia or FN in other nodules by CNB is recognized and should be evaluated in future to understand the meaning.