Overview of foreign clinical guidelines for the use of fine-needle aspiration biopsy of thyroid nodules

Fine-needle aspiration biopsy (FNA) is the most accurate and cost-effective method for evaluating thyroid nodules. FNA results are useful for stratifying the risk of malignant neoplasms and provide key information to determine the appropriateness of an operation. However, we should keep in mind that FNA is an invasive diagnostic method, so there is a possibility of complications. There is a likelihood of nondiagnostic, false positive and false negative results that can lead to a late or unnecessary operation. We see a growing incidence of thyroid nodules, associated mainly with the increased availability of ultrasound diagnostic of this organ. So the leading organizations involved in the development of clinical guidelines for diagnostics and treatment of thyroid pathologies suggest limiting the conduct of FNA. The use of this method in some cases is not necessary and at times can be even dangerous to a patient. When making clinical decisions, sonographic patterns of thyroid nodules and individual anamnestic and clinical factors of the patient should be considered. For small thyroid nodules, the FNA in most cases is not necessary. It is more rational to make a decision based on sonographic patterns rather than be guided by a threshold node size of > 1 cm. The specific sonographic patterns of malignancy are: presence of calcifications, irregular margins, hypoechoic nodule, taller-than-wide shape, metastases to the cervical lymph nodes, and extrathyroidal extension. The totality of these signs is useful for stratifying the risk of malignancy of the thyroid nodules and deciding on the need for FNA.