Abstract
Background Thyroid nodules are a common medical problem worldwide. This study aims to investigate and elucidate the relationship between thyroid-stimulating hormone (TSH), thyroxine (T4), and triiodothyronine (T3), and malignant thyroid nodules. Methods This prospective cross-sectional study was conducted at a public specialist hospital in Saudi Arabia from February 2020 to February 2021. All thyroid nodules were scanned using ultrasound imaging, and the largest diameter was measured for each and classified according to the American College of Radiology (ACR) Thyroid Imaging Reporting and Data System (TIRADS) classification system. Thyroid function tests TSH, T3, and T4 were measured. Definitive diagnoses of thyroid nodules were given based on cytology. A one-way analysis of variance (ANOVA) test was used to compare means, and cross-tabulation was used to correlate the variables in the study. Results A total of 222 patients participated in this study; 23.42% were male and 76.57% were females. The mean age was 44.73 ± 13.31 years (range: 18 to 85 years). The percentage of malignancy was 20.6%, 36.3%, and 91.2% in TIRADS 3, TIRADS 4, and TIRADS 5, respectively. A weak positive linear relationship was noted between nodule size and TSH (R(2)= 0.012). The study demonstrates that TSH increases in malignant nodules more than in benign nodules, while T4 and T3 are decreased in malignant nodules. Conclusion The level of TSH increases in patients with malignant thyroid nodules more than in benign nodules, which can be used as a predictor of malignancy, while T4 and T3 reduced in malignant nodules with an ambiguous relationship.