A Study on Ultrasonographic Evaluation of Thyroid Lesions and Its Correlation With Fnac to Detect Malignancy

Background: Thyroid nodules are extremely common with a prevalence of about 20-76% of the adult population based on detection by ultrasonography. While the majority of thyroid nodules are benign, accurate differentiation from malignant lesions remains crucial for appropriate management and patient outcomes. Methodology: This prospective observational study was conducted at the Radiology Department of Hind Institute of Medical Sciences, Sitapur, over 18 months. A total of 138 patients aged 10-75 years with thyroid swelling were included. Highresolution ultrasonography was performed using linear transducers, followed by ultrasound-guided fine-needle aspiration cytology (FNAC). Nodule characteristics including size, shape, margins, echogenicity, calcifications and vascularity were assessed. Statistical analysis was performed using SPSS version 29 with sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) calculated. Results: Out of 138 patients, 112 (81.16%) were females with a male-to-female ratio of 1:4.3. The majority of patients were in the 20-29 years age group (28.2%). On ultrasonography, 124 (89.9%) cases were diagnosed as benign with 122 (98.4%) confirmed benign on FNAC, while 14 (10.1%) were suspected malignant on USG with 10 (71.4%) confirmed malignant on FNAC. The most common benign condition was colloid goiter (35.56%) and papillary carcinoma was the most common malignancy (3.70%). USG demonstrated 83.33% sensitivity, 96.83% specificity, 71.43% PPV, 98.39% NPV and 95.65% accuracy. Strong correlation was found between USG and FNAC diagnoses (p < 0.0001). Conclusion: Ultrasonography serves as a highly reliable first-line imaging modality for thyroid nodule evaluation with excellent specificity and accuracy. The combination of USG and FNAC provides a robust diagnostic framework for distinguishing benign from malignant thyroid lesions, reducing unnecessary procedures while ensuring timely intervention for malignant cases.