Correlation of ultrasound features in the TIRADS scoring system with cytological findings in the FNAC of thyroid nodules and their association with the metabolic status

Background Thyroid nodules were widely encountered in the population, and the selection of thyroid nodules for fine needle aspiration cytology (FNAC) remains confusing. It is essential to investigate the risk factors associated with thyroid nodules. Aim of work This study aimed to evaluate the accuracy of the American College of Radiology-Thyroid Imaging Reporting and Data System (ACR-TIRADS) scoring system in distinguishing malignant thyroid nodules from benign ones and its association with cytological examination of the FNAC of the thyroid nodules. Additionally, we seek to investigate any potential association between thyroid nodules and some metabolic derangements. Patients and methods The study included 111 Egyptian patients with euthyroid nodules whom were subjected to history taking, clinical examination, and laboratory investigations including thyroid profile, fasting blood sugar (FBS), glycosylated hemoglobin A1c (HbA1c), and lipid profile. Thyroid ultrasound and FNAC were done for all patients. Categorization of each nodule was done according to the TIRADS. Cytopathological diagnosis was done by Bethesda system cytology classification. Results There were 19 malignant and 92 benign nodules. There was a statistically significant difference between benign and malignant nodules regarding TIRADS classification, taller-than-wide shape, solidity, border, presence of peripheral calcifications, or punctuate echogenic foci (p < 0.05). Taller-than-wide shape had the highest specificity followed by irregular margin (94.6% and 92.6%, respectively). Sensitivity, specificity, PPV, and NPV for ACR-TIRADS versus cytopathology were 73.7%, 57.6%, 26.4%, and 91.4% respectively with overall accuracy of 60.4%. The high sensitivity and NPV of the US-based TIRADS classification system have excellent utility for correctly classifying nodules as positive for malignant disease. As regards risks for thyroid nodules, results showed that most of the study population were obese [Body Mass Index (BMI) = 31.6 +/- 6.3, Waist circumference (WC) = 107.4 +/- 13.9]. TSH and hypercholesterolemia did not show a significant association with thyroid malignancy. Conclusion ACR-TIRADS classification is of high significant value in classifying nodules as positive for malignant disease and for predicting the absence of malignant disease, reducing unnecessary nodule FNAC. Hypercholesterolemia and TSH value were not significantly associated with malignant thyroid nodules.