Preoperative serum thyroglobulin levels as a predictor of thyroid carcinoma

ABSTRACT

Background: Incidence of thyroid nodules varies according to the methods of diagnosis, 4-7% by palpation and 17-67% by high resolution ultrasound. The gold standard of diagnosis for thyroid nodules is fine needle aspiration (FNA); however, fine needle aspiration cytology (FNAC) alone is insufficient to detect cancer because of inadequate cytology (5-15%) and in cases of follicular neoplasm (15-25%) where only surgery is diagnostically conclusive. Therefore, other factors in addition to FNA should be considered to predict malignancy. This study was done to evaluate the association between elevated pre-operative thyroglobulin levels and histopathologically proven thyroid carcinoma.Methods: This retrospective study was conducted in Bowring and Lady Curzon Hospital, from December 2017 to November 2018. All patients above 18 years, undergoing total thyroidectomy, with normal antithyroglobulin levels and with indeterminate thyroid nodules or disease on FNAC were included. Patients proven to have malignancy by FNAC, who underwent hemithyroidectomy and patients with thyroglossal cyst or ectopic thyroid swellings were excluded.Results: A total of 50 patients were included. The Fischer’s exact test shows significant value of 0.037 and also the two-tailed test showed a p value <0.05, hence it is significant to conclude that the mean value of thyroglobulin levels among histopathologically proven malignant thyroid cancers is significantly higher compared to the benign thyroid disease.Conclusions: In addition to thyroid-stimulating hormone, thyroid nodules with elevated thyroglobulin levels were independently associated with the presence of thyroid cancer; therefore, the evaluation of pre-operative thyroglobulin level in patients with indeterminate FNAC might give additional information to predict malignancy.