An overview of TI-RADS systems from a point of view of follicular tumors diagnosis

Abstract

The existing systems for describing thyroid nodules are highly informative and can be applied in routine practice, but suspicious criteria of thyroid nodules are based on the echographic pattern of papillary neoplasia, due to its predominance in the population. Follicular tumors are difficult to be differentiated between adenomas and follicular cancer, both echographically and morphologically. Despite the lower prevalence, this type of tumor has a high risk of aggressive course and relapse of 30–55% and this determines its early detection importance. The analysis of publications from 2009 to 2020 of existing TI‑RADS systems and national guidelines for the diagnosis of thyroid tumors, with an emphasis on the assessment of follicular tumors, was carried out. In Russia, at the beginning of 2021, the national guidelines require the use of EU‑TIRADS 2017, and the introduction of the national RU‑TIRADS is underway. Difficulties remain in the differential diagnosis of follicular tumors of different malignancy potential. It is possible that a combined risk assessment of echography, elastography, cytology, and molecular genetic studies will allow a more reliable stratification of the risks of thyroid nodules at the preoperative stage.