Comparison of Fine needle aspiration followed by histopathology and sonographic features of thyroid nodule to formulate a diagnosis: A cross-sectional study

Abstract

Thyroid nodules are solid lumps filled with fluid that develop inside the thyroid gland. Due to their small size, the majority of them go undetected and are asymptomatic. However, some of them are cancerous. Objectives: To compare the diagnostic accuracy of Fine needle aspiration followed by histopathology and sonographic features of thyroid nodule Methods: In this study, 274 participants were included. All of them were detected with the solitary euthyroid nodule. All the patients considered in the present study had normal values of T4 and TSH as euthyroid nodules were supposed to be studied. All the participants were subjected to undergo a USG as per the TIRADS system and FNAC wherever it was applicable. The biopsy report of the excised sample was considered a gold standard. Result: The classification of FNAC was more specific than the TIRADS system, however, the sensitivity of both the classification was the same. Micro-calcification was most specific and sensitive in the individuals that underwent a USG. Irregular margins had a specificity of 88% and nodules taller-than-wider in shape were 91% specificity. A total of 7 patients had shown benign features on cytology, whereas, they were suspiciously malignant on USG (TIRADES 4 and 5) and showed malignancy in final evaluation after the surgery. Conclusion: The sensitivity of both FNAC and USG in the diagnosis of malignancy of thyroid nodule is equal, however, the specificity of FNA is more (90%). FNAC is a minimally invasive procedure that can be opted for the differentiation of benign and malignant lesions with an accuracy of 86%. Patients showing high-risk features on sonography are subjected to repeat the FNAC and they should also be referred for a surgical biopsy to make a definitive diagnosis.