Evaluation of Fine Needle Aspiration Biopsy (FNAB) Results in Macrocalcified Thyroid Nodules

Objective: Thyroid nodule is the most common disease of the thyroid gland and is closely associated with thyroid cancer. The gold standard method in diagnosis is Fine Needle Aspiration Biopsy (FNAB). Although the relationship between nodules containing microcalcification and malignancy is well known, there is no consensus on the relation of nodules with macrocalcification to malignancy and the adequacy of FNAB. In this study, it was aimed to compare the results of FNAB of nodules with and without macrocalcification in US examination. Methods: In this retrospective study, 466 nodules undergoing FNAB of 450 patients who applied for biopsy were included in the study. The demographic characteristics of the patients, US features of the nodules and cytopathology results of FNAB in the Bethesda classification were recorded. Nodules were divided into two main groups as calcified and non-calcified. US features and cytopathology results of the groups were compared. Results: Transverse sizes of calcified nodules were found to be larger than non-calcified ones (p = 0.003). In addition, solid composition, hypoechoic and prominent hypoechoic echogenicity, and irregular border feature were found with a higher rate in the calcified group (p <0.001). No significant difference was found between insufficient sample/non-diagnostic cytology (Bethesda-1) ratios in both groups (19.2% and 14.7%). Cytopathologically, number of malignant and suspected malignant nodules (Bethesda 5 and 6) were found to be higher in the calcified group (p=0.05). Conclusion: According to the results of this study, detection of macrocalcification in thyroid nodules in US examination does not cause a significant increase in insufficient FNAB results. However, the presence of macrocalcification increases the risk of malignancy of the thyroid nodule.