Fine-needle Aspiration Versus Core Needle Biopsy for Diagnosis of Thyroid Malignancy and Neoplasm: a Matched Cohort Study

Objectives: To compare the diagnostic performances of fine-needle aspiration (FNA) and core needle biopsy (CNB) in the diagnosis of thyroid malignancy and neoplasm in patients who underwent surgery for thyroid nodules.

Methods: This retrospective study was approved by the institutional review board, and the need to obtain informed consent was waived. 3192 patients who underwent FNA (n = 3048) or CNB (n = 144) for diagnosis of thyroid nodules and then proceeded with surgery were included. Surgical pathologic diagnosis was the reference standard. Diagnostic performances of FNA and CNB to predict malignancy and neoplasm were compared. Propensity score matching was used to match patients with FNA with those with CNB because there were significant differences in the number of nodules and nodule characteristics between the FNA and CNB groups.

Results: Before matching, the sensitivity and accuracy of FNA were significantly higher or comparable with those of CNB, and the specificity, negative predictive value and positive predictive value were comparable. After matching, the diagnostic performances were similar, with the exception of specificity for predicting neoplasm being higher with CNB than with FNA.

Conclusion: FNA showed comparable diagnostic performance to CNB; therefore, there may be no benefit in performing CNB to diagnose papillary thyroid carcinoma and neoplasm.

Key Points: • Diagnostic performances of FNA and CNB for thyroid malignancy and neoplasm were compared. • FNA showed comparable performances to CNB both before and after statistical matching. • There may be no benefit in performing CNB, given the comparable performances.