INTRODUCTION Non-diagnostic results of fine needle aspiration biopsy (FNAB) remain an important limitation of this technqiue. The aim of our study was to evaluate the results of core needle biopsy (CNB) of thyroid nodules and its effectiveness in non-diagnostic FNAB cases. METHODS CNBs were performed in 1,000 patients (154 male, 846 female; mean age: 50.2 years, range: 18-86 years) with a spring loaded 20G needle. Of these, 143 had initially had FNABs that were insufficient for evaluation. The CNB reports were reviewed. Patients with suspicious or malignant CNB results underwent total thyroidectomy. RESULTS When considering all 1,000 CNBs, the non-diagnostic rate was 1.5% (15/1,000). However, when the first 100 cases were eliminated as a learning curve, this reduced to 0.9% (8/900). Of the 143 cases with initial FNABs that were non-diagnostic, 0.7% (1/143) were also non-diagnostic on CNB. Twelve patients underwent surgery because of malignant CNB reports and all of these cases were confirmed as malignant by the postoperative pathology specimen results (100% accuracy). There were no major complications although three self-limiting minor complications were observed. CONCLUSIONS CNB is a safe and accurate method. It is more diagnostic than FNAB for nodular thyroid disease.
Keywords: Core needle biopsy; Fine needle aspiration; Nodule; Thyroid.