OBJECTIVES: The purpose of this study was to investigate the level of conclusive results obtained with ultrasound (US)-guided core needle biopsy (CNB) and how this method should be applied for diagnosis of thyroid nodules.
METHODS: From January 2013 to November 2014, US-guided CNB was performed in 84 thyroid lesions of 83 patients. Based on CNB pathologic reports, thyroid nodules were divided into 2 categories: conclusive (nodules reaching a definite pathologic diagnosis suggesting benignity or malignancy) and inconclusive (nodules that were not able to reach a definite diagnosis because of ambiguous results). Medical records and US examinations were reviewed and compared.
RESULTS: The mean age of the 83 patients ± SD was 49.7 ± 14.1 years. Of the 84 thyroid nodules, 73 (86.9%) were diagnosed as benign or malignant and 11 (13.1%) as inconclusive by CNB pathologic analysis. Among the 11 nodules with inconclusive results, the possibility of a follicular neoplasm was suggested in 8 nodules (72.7%). No significant difference was seen in tumor size and US features when comparing the nodules with conclusive and inconclusive results (all P >.05).
CONCLUSIONS: Ultrasound-guided CNB may have supplemental roles in addition to US-guided fine-needle aspiration for diagnosis of selected cases. A considerable proportion of inconclusive results are seen on US-guided CNB, especially for diagnosis of follicular lesions, which must be considered when using this method for diagnosis of thyroid nodules.