Low Nondiagnostic Rate for Fine‐Needle Capillary Sampling Biopsy of Thyroid Nodules

Abstract

This study examined the hypothesis that sonographically guided fine-needle capillary thyroid biopsies performed by an experienced operator and with constant technique on nodules that meet the Society of Radiologists in Ultrasound criteria warranting biopsy can result in a nondiagnostic rate that is significantly lower than prior published reports. We retrospectively reviewed the sonographic and pathologic reports from 228 consecutive sonographically guided fine-needle capillary thyroid biopsies performed during a 3-year interval by a single operator with more than 15 years of experience performing fine-needle capillary thyroid biopsies. There were no exclusion criteria. Sonographic and pathologic reports from all nodules biopsied were included in the analysis. The radiologist's protocol included 6 fine-needle capillary biopsies, each with 20 passes of the needle into the periphery and/or solid components of the nodule. The cytologic specimens were reviewed off-site in adherence with the Bethesda system for reporting thyroid cytopathologic findings and classified as diagnostic or nondiagnostic. The nondiagnostic rate in this study was compared with the nondiagnostic rates in prior published reports. Among the 228 fine-needle capillary thyroid biopsies performed during the study interval, cytologic analysis showed 1 nondiagnostic biopsy, yielding a nondiagnostic rate of 0.4%. This rate was significantly lower than previously published reports (P < .001). Sonographically guided fine-needle capillary biopsies of the thyroid performed by an experienced radiologist can result in a nondiagnostic rate of less than 1%. This finding warrants further investigation into the reasons for the discrepancy between the results of this study and other previous reports.