The Role of Core Needle Biopsy for Thyroid Nodules with Initially Indeterminate Results on Previous Fine-Needle Aspiration: A Systematic Review and Meta-Analysis.

Abstract

Sonography-guided fine-needle aspiration leads to relatively frequent cases of indeterminate cytology for the diagnosis of thyroid nodules. Our aim was to evaluate the efficacy and safety of core needle biopsy for the examination of thyroid nodules with initially indeterminate results on fine-needle aspiration. A computerized search of the MEDLINE and Embase databases was performed to identify relevant original articles. Studies investigating the use of core needle biopsy for thyroid nodules with initially indeterminate results on previous fine-needle aspiration were eligible for inclusion. The pooled proportions for nondiagnostic results, inconclusive results, malignancy on core needle biopsy, the ability of core needle biopsy to diagnose malignancy, and the related complications of the procedure were analyzed. The meta-analytic pooling was based on a random-effects model. Nine eligible studies, involving 2240 patients with 2245 thyroid nodules, were included. The pooled proportion for nondiagnostic results was 1.8% (95% CI, 0.4%-3.2%), and the pooled proportion for inconclusive results was 25.1% (95% CI, 15.4%-34.9%). The pooled proportion for malignancy was 18.9% (95% CI, 8.4%-29.5%). With regard to the diagnostic performance for malignancy, the sensitivity of core needle biopsy varied, ranging from 44.7% to 85.0%, but the specificity was 100% in all cases. No major complications of core needle biopsy were observed. The relatively small number of included studies and retrospective nature were limitations. Core needle biopsy has low nondiagnostic result rates and high specificity for the diagnosis of malignancy. It is a safe diagnostic technique with a higher diagnostic yield, especially when molecular testing is not available or fine-needle aspiration did not yield enough cells for molecular testing.