Fine-needle aspiration bio psy and Bethesda classifi cation in the diagnostics of the tumours of the thyroid gland – a retrospective study

Introduction: Thyroid nodule is a pathology with a prevalence of 19–68% of the population, with a thyroid gland carcinoma proven in 7–15% of these cases. Bethesda classifi cation is a standardized system for cytology fi ndings evaluation. Aim of work: The aim of our work was to compare a predicted preoperative dia gnosis including Bethesda classifi cation and the fi nal histology results, to defi ne malignancy risk for Bethesda categories and to compare our fi ndigs with foreign papers. Material and methods: A retrospective, observational study. In a group of 330 patients with performed operation on the thyroid gland (total thyroidectomy or hemithyroidectomy) at the ENT department of the University hospital in Pilsen between 2016 and 2017 there was a group of 180 patients (147 female and 33 male patients) with preoperatively known Bethesda category. We have compared an expected dia gnosis and postoperatively known histology dia gnosis, determined a risk of malignancy rate for each category of Bethesda classifi cation and compared our results with a foreign literature. Results: In the group of our patients, we have determined a risk of malignancy rate for Bethesda I. category as 14.29%, same as for Bethesda II. For Bethesda III. as 15.79%, Bethesda IV. as 10.64%, Bethesda V. as 52.17% and Bethesda VI. category as 100%. Conclusion: Fine- -needle aspiration bio psy of thyroid gland nodules is a basic dia gnostic method, which facilitates categorization and stratifi cation of a risk of malignancy in cytological fi ndings. In our group of patients, a risk of malignancy rate diff ers in Bethesda I. and II. category, our risk of malignancy rate is higher compared to foreign literature, which, we believe, is a statistical error due to a rather small set of patients. Key words thyroid nodule – fine-needle aspiration bio psy – Bethesda classifi cation – risk of malignancy rate