Endocrine Abstracts

Background: Thyroglobulin, serves as a specific tumor marker following thyroidectomy in differentiated thyroid cancer (DTC) patients. However, its role as DTC predictor in patients with thyroid nodules (TN) is controversial.

Aim: We aimed to assess the potential role of preoperative serum thyroglobulin concentration to predict DTC in patients who were operated for thyroid nodular disease.

Methods: This retrospective study included patients who had partial or total thyroidectomy between January 2014 and May 2019, with preoperative diagnosis of benign multinodular goiter (MNG) or a TN with indeterminate cytology (INC; Bethesda system 3/4 categories). We compared patients for demographic, clinical, imaging, and biochemical data according to their final diagnosis: DTC or benign TN disease. Further statistical analysis included odds ratios calculation and receiver-operator curves (ROC) analysis.

Results: Of 131 patients who met inclusion and exclusion criteria, the indication for surgery was benign MNG in 69, and TN with INC in 62 patients. Final diagnosis of DTC was reported in 18/69 (26%) and 30/62 (48%) of patients with preoperative diagnosis of benign MNG and INC-TN, respectively. Preoperative Median thyroglobulin was 148.5 ng/ml (IQR 67.8-1158.5) vs. 190 ng/ml (IQR 62.4-574), in malignant and benign MNG respectively (P= 0.97), and 160.5 ng/ml (IQR=82.2-536.7) vs. 205.5 ng/ml (IQR= 65.2-821.5) in malignant and benign INC-TN respectively (p= 0.93). Nodule diameter, TSH level, and thyroglobulin did not differ between patients with final diagnosis of DTC versus those with benign histology.

Conclusion: Preoperative serum thyroglobulin alone is insufficient to differentiate preoperatively between malignant and benign thyroid disease.