Beyond Size: Integrating Ultrasonographic Features and FNAB Cytology to Predict Thyroid Malignancy—A Retrospective, Single-Center Study

<b>Background/Objectives:</b> This study aimed to evaluate the relationship between preoperative clinical, ultrasonographic, and cytologic findings and postoperative histopathology in patients with thyroid nodules, and to determine diagnostic factors associated with malignancy. <b>Materials and Methods:</b> A retrospective analysis was conducted on 100 patients who underwent thyroid surgery between September 2012 and April 2014. Preoperative data-including clinical examination, thyroid function tests, and high-resolution ultrasonography-were compared with fine-needle aspiration biopsy (FNAB) results and final histopathology. Ultrasonographic features (echogenicity, calcification, vascularity, and margin) were analyzed for their association with malignancy. Statistical tests included chi-square, <i>t</i>-test, and correlation analysis (<i>p</i> < 0.05 considered significant). <b>Results:</b> Among 100 patients (79 females, 21 males; mean age 47.5 ± 13.9 years), 29 (29%) had benign and 71 (71%) malignant histopathology. Malignancy was significantly associated with older age (<i>p</i> = 0.025), smaller nodule size (<i>p</i> = 0.019), hypoechogenicity (<i>p</i> = 0.001), microcalcifications (<i>p</i> = 0.014), and irregular margins (<i>p</i> = 0.017). FNAB showed a strong correlation with final histopathology (r = 0.65, <i>p</i> = 0.001). The overall sensitivity and specificity of FNAB were 25.4% and 82.8%, respectively. <b>Conclusions:</b> Hypoechogenicity, microcalcifications, and irregular margins were the most reliable ultrasonographic predictors of malignancy. FNAB remains a highly specific but variably sensitive diagnostic tool, and its accuracy increases when interpreted in conjunction with ultrasonographic findings. Integrating cytology with structured imaging systems such as ACR TI-RADS and Bethesda classification enhances diagnostic precision in thyroid nodule evaluation.