The predictive value of selected ultrasound features in evaluating malignancy in thyroid nodules

Abstract

Background: Thyroid ultrasound has been widely used to differentiate benign from malignant nodules; many investigators have tried to point out few ultrasonographic features in order to identify those lesions, which are at a higher risk of malignancy. Objectives: To evaluate the efficacy of selected conventional ultrasound (US) features of thyroid focal lesions useful for predicting malignancy and establishing indications for fine-needle aspiration cytology (FNAC). Patients and Methods:Two hundred and four consecutive patients with thyroid nodules who visited the outpatient clinic of the surgical department of Tikrit University teaching hospital for the period from January 2011 to April 2014, and who underwent surgery for clinical suspicion of malignancy; were examined by US before thyroidectomy. Conventional US evaluated the presence of a halo sign, hypoechogenicity and microcalcifications. Results: On histology, 60 nodules were diagnosed as malignant and 148 as benign nodules. On US, the echographic pattern most predictive for malignancy was microcalcification (P = 0.0001; specificity 78.0%; sensitivity 67.6%). The most specific combination on US, absent halo sign/microcalcifications (P < 0.005; specificity 92.2%, sensitivity 27.6%). Conclusion: Findings on US become effectively predictive for malignancy only when multiple signs are simultaneously present in a thyroid nodule. Thus the predictive value of these techniques increases at the expense of their sensitivity.