Diagnostic accuracy of combined clinical, ultrasonography and fine needle aspiration cytology for thyroid swelling assessment

ABSTRACT

The present study was designed to evaluate applicability of combination of clinical examination, neck conventional ultrasonography [US] and US-guided fine needle aspiration cytology [FNAC] as a strategy for assessment of thyroid swellings and differentiating between malignant and benign thyroid lesions. The study included 50 patients [5 males and 45 males with a mean age of 37.1+/-6.9 years] with nodular thyroid swelling. All patients underwent complete history taking, full clinical examination, neck US and US-guided FNAC. All patients underwent thyroidectomy and excised specimens were examined histopathologically. All patients passed smooth intra- and postoperative course apart from 4 cases that developed postoperative hematoma collection, one of them required evacuation. Histopathological examination defined 5 [10016] papilary and one [2%] follicular carcinoma and 44 [88%] benign nodules. Clinical examination detected 14 patients [28%] with criteria of suspicious malignancy while the other 36 patients showed no criteria of suspicious malignancy. Clinical diagnosis could define malignant thyroid lesions with sensitivity 66.7%, specificity 77.3% and accuracy 76%. The receiver operating characteristic [ROC] curve analysis for the diagnostic yield of clinical findings for differentiating between malignant and benign thyroid as judged by the area under the curve [AUC] showed AUC=0.652. Conventional US diagnosis depending on US signs of malignancy revealed that 2 malignant lesions were solid, hypoechoic nodules with blurred margins, no halo sign and with fine calcification, another 2 malignant nodules were solid, isoechoic nodules with blurred margins, no halo sign and with coarse calcification, whereas the remaining 2 malignant nodules were solid, hypoechoic nodules with well-defined margins, present halo sign and with coarse calcification, ROC curve analysis for the diagnostic yield of each US finding separately showed that presence of fine calcification had the highest diagnostic yield [AUC=0. 739], presence of blurred margin and absent halo sign [AUC=0. 72], internal echogenecity [AUC=0.667] and echostructure [AUC=0.527]. Fine needle aspiration was carried out successfully in 48 patients with a success rate of 96% and diagnosed 4 specimens as papillary carcinoma, 5 as follicular neoplasm and 39 specimens as hyperplastic nodules. FNAC could diagnose malignancy with sensitivity 83.3%, specificity 90.5% and accuracy rate of 89.6% and ROC curve analysis for the diagnostic yield of FNAC showed AUC=0.871. It could be concluded that the combined dependence on clinical judgment, the result of US-guided FNAC and the presence of blurred margin of the nodule associated with absence of Halo sign and micro-calcification using conventional neck US provided the most significant diagnostic yield for differentiating between malignant and benign thyroid lesions