Accuracy of Ultrasonic Thyroid Nodules‘ Calcifications in Detection of Malignancy in Northern Iran

Abstract

Background and objective: This study, which was conducted at _Imam Hospital, Sari in Iran, aimed to evaluate the morphology of thyroid nodule calcification by ultrasound and its relationship with the type of pathology to determine whether the characteristics of calcifications detected by ultrasound have a predictive value for malignancy of thyroid nodules. Materials and Methods: In the diagnostic study, 390 patients with thyroid nodules underwent ultrasonography. Fine-needle aspiration (FNA) biopsy was performed on 413 nodules, and those with calcifications were separated from the study and matched to the type of pathology. Each echogenic particle with or without posterior shadow was considered as calcification; particles with a size of <2 mm were considered microcalcification and those with a size of >2 mm were macrocalcification. Other forms of calcification were also identified. Results: Among the 413 nodules examined, 97 cases had calcification, including 70 cases (73.7%) with macrocalcification and 27 (26.3%) with microcalcification. Pathology revealed 80 benign (82.5%) and 17 malignant (17.5%) nodules. A significant difference was observed between macrocalcification and microcalcification pathologically, so that nodules with microcalcification had higher rates of malignancy than those with macrocalcification (P < 0.001). The sensitivity and specificity of microcalcification and macrocalcification were 65%, 80% and 35%, 35%, respectively. However, the difference between central and peripheral calcifications was not significant in relation to malignancy (P = 0.07). Conclusion: Observation of microcalcification in the thyroid nodules is important and the probability of malignancy is higher in these nodules.