Should Core Needle Biopsy be Used in the Evaluation of Thyroid Nodules?

Fine needle aspiration (FNA) is the first choice in thyroid nodules suspected of harboring malignancy on sonography in routine practice. However, sampling with core needle biopsy (CNB) is also being used, especially in cases with repeated nondiagnostic/indeterminate diagnoses. The aim of this study was the retrospective evaluation of CNB samples. A total of 604 thyroid CNB samples registered in the Department of Pathology at Bezmialem Foundation University Medical Faculty within the 1-year period between June 2014 and June 2015 were re-evaluated by correlation with previous FNA and later resection results. CNB was divided into diagnostic groups of insufficient, malignant, suspicious for malignancy, no evidence of malignancy/benign, atypia of uncertain significance (AUS)/follicular lesions of uncertain significance (FLUS), and follicular neoplasm (FN)/suspicious for follicular neoplasm (SFN). Among the 604 cases, 15 cases (2.48 %) were classified as malignant and 9 cases (1.49 %) as suspicious for malignancy. No evidence of malignancy was seen in 512 cases (84.76 %). There were 26 (4.3 %) cases in the AUS/FLUS-FN/SFN group, and the sample was inadequate in 42 cases (6.95 %). Resection was performed for 17 of the cases classified as malignant or suspicious for malignancy, and all were found to be malignant. There were also 10 resected cases with a diagnosis of no evidence of malignancy, and all were found to be benign. We think that sampling with CNB may be useful especially in repeating inadequate biopsies or cases diagnosed with AUS/FLUS that have hesitations regarding clinical management. Larger series including comparisons with FNA and resection results are required.