RESUMO
INTRODUCTION: Thyroid cancer is the most common endocrine system cancer. Although fine-needle aspiration biopsy is the most commonly used method for diagnosis, it is not always sufficient. The aim of this study was to investigate the influence of preoperative serum thyroglobulin (Tg) concentration on differentiated thyroid cancer risk. MATERIAL AND METHODS: A total of 133 patients who underwent total thyroidectomy due to various indications at the Ear-Nose-Throat Department, Ataturk University Medical School, between April 2015 and December 2015, were included in this prospective study. Histopathological diagnosis and preoperative Tg levels were compared. Receiver operating characteristic (ROC) analysis was used for detection of the cut-off to discriminate malignant from benign thyroid masses using preoperative Tg as a variable. RESULTS: Malignant pathology (differentiated thyroid carcinoma) was detected in 59 out of 133 patients (44.4%) and benign pathology in 74 (55.6%). A statistically significant difference in preoperative Tg value was detected between malignant and benign cases (p < 0.05). CONCLUSION: The prevalence of differentiated thyroid carcinoma was higher among patients with a preoperative serum Tg value > 188.5 ng/mL, and this may thus be used as a marker for the diagnosis of this malignancy.