Thyroid Cancer in Multinodular Goiter: An Analysis of Prevalence and Associated Risk Factors

Background: Despite being often asymptomatic, multinodular goitre (MNG) can harbor malignancy, with reported cancer rates ranging widely from 3% to 35%. Fine-needle aspiration cytology (FNAC), though widely used, has limitations in accurately assessing multiple or deeply located nodules. The purpose of the study was to determine the prevalence of thyroid cancer in multinodular goitre and identify associated risk factors influencing malignancy. Aim of the study: The aim of the study was to determine the prevalence of thyroid cancer in multinodular goiter and identify associated risk factors influencing malignancy. Methods: This retrospective study was conducted at the Department of Otolaryngology-Head & Neck Surgery, Bangladesh Medical University, Dhaka, Bangladesh, (March 2023–February 2025), involving 120 adult patients with multinodular goiter undergoing thyroidectomy. Preoperative assessments included clinical examination, hormone analysis (FT3, FT4, TSH), ultrasound, and FNAC. Histopathology confirmed diagnoses. Data were analyzed using SPSS v25, with Chi-square tests and FNAC diagnostic metrics, and p < 0.05 considered significant. Results: This study of 120 multinodular goiter patients found 80% benign and 20% malignant cases, with papillary carcinoma being the most common. Risk factors for malignancy included male sex, nodules >3 cm, unilateral nodules, and suspicious ultrasound findings. FNAC showed a sensitivity of 85.0%, specificity of 82.0%, and overall accuracy of 80.0%, demonstrating its effectiveness in preoperative evaluation. Conclusion: This study demonstrates that thyroid cancer is prevalent in 20% of multinodular goiter cases, with FNAC proving to be a highly accurate diagnostic tool for preoperative evaluation.