RESUMEN
Thyroid cancer is the most common malignant tumor of the endocrine system. An increase in the incidence of thyroid cancer has been noted over the past decade, mainly due to papillary cancer. The influence of environmental factors, increased availability of medical care, including sensitive diagnostic tests, such as ultrasound and fine - needle aspiration (FNA), can affect the fact of the growth of this incidence. Palpation of thyroid gland has very low diagnostic value for detecting thyroid cancer, while thyroid ultrasound and FNA can detect malignant tumors in 20% of cases. Today, the FNA is the fastest, most accurate, economically accessible, and quite safe method for cytological diagnosis of the thyroid nodules. And molecular genetic testing of FNA samples could serve as an additional reliable diagnostic tool in the case of atypia of undetermined significance.