Serum Thyroid-Stimulating Hormone (sTSH) Levels as a Predictor of Thyroid Malignancy: A Retrospective Analysis of 102 Patients

Introduction Thyroid nodules are common, with a significant proportion presenting with indeterminate cytology on fine-needle aspiration cytology (FNAC). Thyroid-stimulating hormone (TSH) has been proposed as a potential biochemical marker to aid in malignancy risk stratification, though findings across studies remain inconsistent. This study evaluates the association between preoperative serum TSH (sTSH) levels and histopathologically confirmed malignancy in patients undergoing thyroidectomy. Method We conducted a retrospective observational study on 102 patients who underwent total or partial thyroidectomy between 2019 and 2022 at a tertiary care centre. Preoperative sTSH levels, FNAC results, ultrasound characteristics, and final histopathological outcomes were analysed. Statistical analysis included independent t-tests and chi-squared tests to assess associations. Results Of the 102 patients, 18 (17.6%) were diagnosed with malignant lesions, predominantly papillary thyroid carcinoma. The mean sTSH level was slightly higher in malignant cases (1.378 μIU/mL) compared to benign cases (1.350 μIU/mL), but this was not statistically significant (p = 0.68). Histopathological features such as lymphovascular invasion (LVI) and extrathyroidal extension (ETE) were significantly more common in malignant cases (p < 0.01). FNAC had limited predictive accuracy, correctly identifying 61.1% of malignant cases. Conclusion Whilst no significant association was found between sTSH levels and malignancy, features such as LVI, ETE, and certain ultrasound characteristics remain valuable predictors. sTSH may be useful as part of a broader, multimodal risk assessment approach but should not be relied upon as a standalone diagnostic tool.