Publication

Abstract : Background: Thyroid nodules are the most frequent endocrine disorder and is a major healthcare problem. There is a dilemma in management of those patients with FNAC reported as indeterminate cytology. Currently there is no recommendation for the use of serum TSH level to assess risk of malignancy in patients with newly diagnosed thyroid nodules. Methods: A retrospective cross sectional study of a cohort of patients who presented to our department with complaints of thyroid swelling and underwent thyroidectomy between January 2015 to January 2020. The charts of these patients were reviewed and the required study data was tabulated and analysed. Results: FNAC diagnosis of indeterminate cytology was made in 394/ 3283 (12%) nodules. Among these 90 were excluded and in the remaining 304 cases that met our inclusion criteria histopathological diagnosis of thyroid malignancy was made in 93 (30.6%).Those patients with malignancy confirmed on final histopathology study showed a higher serum TSH levels.(2.93 ± 1.067 vs. 1.73 ± 1.051, p = <0.001) The 304 cases were subdivided into four quartiles to further analyse the predictive role of serum TSH.The first quartile showed a low prevalence of malignancy, accounting for only (10.75%) of the cases; while the last quartile showed a high rate of malignancy accounting for (46.23%) of the cases. On doing the ROC curve analysis, a TSH value of >/=2.185 mIU/L was reached, which can identify patients with malignancy with 74.19% sensitivity and 73.93% specificity. The mean TSH levels of all types of malignant nodules {papillary carcinoma (79.56%), follicular carcinoma (18.27%) and hurthle cell carcinoma (2.15%)} also aligned with our test model (>2.185mIU/L).The quartile based analysis was also in accordance with our general study model with the highest TSH quartile being associated with malignant nodules. Conclusions: Patients with thyroid nodules of indeterminate cytology having TSH levels in the upper quartile (>2.185mIU/L) of the normal range are at a higher risk of thyroid malignancy. Serum TSH levels can be advocated as a simple, cost effective and efficient diagnostic tool for risk assessment and decision making in patients with thyroid nodules of indeterminate cytology.