Clinicoradiological, Cytological and Histopathological Characteristics of Thyroid Nodules: A Retrospective Observational Study

Abstract

Background: Thyroid nodules (TNs) are a common clinical entity with varied presentations and outcomes. Accurate characterisation using clinical, biochemical, radiological, cytological and histopathological parameters is essential for optimal risk stratification and management. Objectives: To characterise TNs across clinical, biochemical, radiological, cytological and histopathological parameters. Methods: This retrospective observational study was conducted at a tertiary care centre in Chennai (January 2024-December 2025). Adult patients with TNs who underwent surgery and had complete preoperative evaluation and postoperative histopathology were included. Data were analysed descriptively. Results: Most patients were female (83%) and aged 31–45 years (47.2%). The majority were euthyroid (79.2%), with a high prevalence of overweight/obesity (62.3%). Ultrasonography predominantly showed multinodular disease (56.6%), nodules >2 cm and low- to intermediate-risk features (Thyroid Imaging Reporting and Data system [TIRADS] 2–3: 62.3%). Fine-needle aspiration cytology (FNAC) revealed Bethesda II (50.9%) as the most common category, with a considerable proportion in Bethesda III-VI. Histopathology demonstrated predominance of papillary (35.8%) and follicular (34%) carcinomas, with low rates of aggressive features, though multifocality (35.8%) and lymph node metastasis (22.6%) were noted. Conclusion: TNs were more frequent in females, especially in middle age, with most being benign, though some showed malignant potential. Higher TIRADS and Bethesda categories correlated well with malignancy, supporting the utility of Ultrasonography (USG) and FNAC as an effective preoperative diagnostic tool. In this surgically selected cohort, benign cytology did not reliably exclude malignancy on histopathology, emphasising that integrated assessment remains essential.