Pre-operative serum TSH level estimation for predicting malignant nodular thyroid disease

Abstract

Background: the aim of this study was to assess the value of serum thyroid–stimulating hormone (TSH) levels in predicting malignancy in patients with nodular thyroid disease (NTD). Objective: The aim was to examine the relationship between preoperative TSH and differentiated thyroid cancer (DTC).Patients and Method: all patients with NTD who were admitted in the first surgical unit of Baghdad teaching hospital and assessed for preoperative TSH level before subjecting them for thyroidectomy from first of April 2014 to 31 of January 2016, were included in the study. A preoperative database sheets including Age, gender, nodule size, and pathology were evaluated. Logistic regression analysis was used to determine which factors were predictive of malignancy.Results: 291 patients were included in our study after exclusion of 20 patients,Four patients with histopathological results other than differentiated thyroid cancer (anaplastic, medullary carcinoma) and sixteen patients were on thyroxine therapy.The overall rate of malignancy was 11%.The rate was slightly higher at extremes of age .the mean TSH was higher in the malignant group (2.07 vs 1.07, p=0.02). The rate of malignancy was 40% in patients with TSH level > 5.5 μIU/mL. Logistic regression analysis revealed that TSH level was the only significant risk factor for malignancy.Conclusion: the serum TSH level may be useful in predicting the probability of cancer and optimizing the extent of thyroidectomy in patients with NTD.Keywords: Thyroid stimulating hormone; Thyroid malignancy; Nodular thyroid disease.