Core needle biopsy of thyroid nodules: outcomes and safety from a large single-center single-operator study

Background There currently remains a debate over the use of core needle biopsy (CNB) or fine needle aspiration (FNA) for diagnosis of thyroid nodules. The major drawbacks of previous CNB studies include heterogeneity of the study population, variable techniques, devices, and operator experience affecting the outcome of the procedure. Purpose To assess the diagnostic performance and safety of CNB of thyroid nodules performed by a single experienced operator in consecutive patients. Material and Methods From January 2012 to December 2012, 538 thyroid nodules that underwent CNB were retrospectively evaluated. All CNB procedures were performed by a single operator with 18 years of experience. The histopathology of the surgical specimens was considered as the standard reference for malignancy. A final diagnosis of benignity was made by surgery, one benign lesion on FNA and/or CNB with no change on follow-up examinations (>1 year) or benign lesion on ≥2 FNA and/or CNB. The diagnostic performance, incidence of technical failure, unnecessary surgery, and complication were evaluated. Results The diagnostic accuracy, sensitivity, and specificity of CNB for malignancy were 92.0%, 85.3%, and 100%, respectively. The non-diagnostic result rate of CNB was 4.8% (26/538) and the inconclusive result rate was 24.3% (131/538). The incidence of technical failure was 0.6% (3/541) and unnecessary surgery was 0.6%. The complication rate was 0.2%, without life-threatening complications. The sensitivity, specificity, and accuracy were 85.3% (156/183), 100.0% (154/154), and 92.0% (310/337), respectively. Conclusion CNB shows a high diagnostic performance for detection of thyroid malignancy and follicular neoplasm, with low rates of technical failure and complications.