The Utility of US-Guided Core-Needle Biopsy in the Diagnosis of Thyroid Nodules

ABSTRACT

Ultrasonography (US)-guided fine needle aspiration biopsy (FNAB) is widely considered to be the diagnostic technique of choice in the assessment of nodular disease of the thyroid gland. Although the accuracy of FNAB analysis approaches 95% where there is an adequate sample, non-diagnostic sampling occurs in 10-20% of cases. Additionally, equivocal pathological results are obtained in 10-30% of cases, and there are limitations in detecting subtypes of certain diseases, such as lymphoma. Generally, US-guided core needle biopsy (CNB) allows for the procurement of a large, grossly visible specimen and a more precise pathological diagnosis. Therefore, US-guided CNB is indicated in the following situations 1) when an inadequate specimen is obtained by FNAB, 2) when FNAB yields indeterminate or inadequate information, 3) when targeting of the lesion is difficult because it is diffuse, and 4) when there is a discrepancy between the imaging findings and the FNAB results. In this article, we describe the situations in which US-guided CNB is useful for diagnosing thyroid lesions.