The current state of the issue regarding preoperative differential diagnosis of noninvasive follicular thyroid neoplasm with papillary-like nuclear features

Abstract

Abstract. The identification of noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) as a separate tumor category in 2016 caused a significant resonance in the cytological community and became the impetus for numerous discussions about the need to review approaches to cytological diagnostics of papillary thyroid carcinoma to prevent overdiagnosis. NIFTP account for approximately 6% of all cases of papillary thyroid carcinoma, in particular, in Europe this figure is about 10%, while in Asia it is only 2%. Most studies on the behavior of NIFTP indicate the absence of metastasis in patients with these tumors. Because such tumors meet the cytomorphological criteria for papillary carcinoma, there is a reasonable concern, that they may be assigned to Bethesda category VI, which, in turn, can lead to the use of more aggressive treatment options than would be appropriate in such cases. Almost 9 years after the introduction of NIFTP these tumors still remain a gray area in the preoperative diagnosis of thyroid gland nodules. To date, there are still no tools for reliable differential diagnosis of NIFTP before the histopathological report is obtained. This uncertainty poses a serious challenge to cytomorphologists and physicians. The literature review aims to reveal the current state of the problem for preoperative diagnosis of NIFTP, analyze the possibility of differentiating NIFTP based
on their ultrasonographic, cytomorphological and molecular characteristics, and consider possible ways to solve the problem of NIFTP in preoperative diagnosis.