Summary of Meta-analyses of Studies Involving TIRADS Classifications (EU-TIRADS, ACR-TIRADS, and K-TIRADS) in Evaluating the Malignant Potential of Focal Lesions of The Thyroid Gland.

Numerous scientific societies around the world have published their TIRADS (Thyroid Imaging Reporting and Data System) classifications that evaluate the risk of malignancy of focal thyroid lesions, presenting different ultrasound features for each category and lesion size thresholds to determine eligibility for biopsy. The use of such risk estimation systems in focal thyroid lesions facilitates the reporting of thyroid ultrasound findings and improves the qualification of focal lesions for fine-needle aspiration biopsy (FNAB). In this publication, the three most popular TIRADS classifications, European - EU-TIRADS, Korean - K-TIRADS, and developed by the American Society of Radiology - ACR-TIRADS, are presented and discussed based on a literature review. The results of available head-to-head statistical analyses comparing the classifications are also presented. The advantage of the EU-TIRADS and K-TIRADS systems is that they include only the most important ultrasound features, so their application is not time-consuming, and the scores are easy to incorporate into clinical practice. ACR-TIRADS, unlike other scales, is based on a unique classification system and represents the most comprehensive classification. Each of the five categories of ultrasound features - morphology, echogenicity, shape, margins, microcalcifications - are evaluated and assigned a score from 0 to 3, with a higher score being associated with a higher risk of cancer. Based on the available data, the greatest benefit has been demonstrated for the ACR-TIRADS classification, which also has implications for minimising the number of unnecessary FNABs. However, limitations related to the heterogeneity of the groups analysed in the study, including differences in the populations studied, inclusion criteria, proportions of patients of either sexes, and the number of malignant lesions analysed, should also be taken into account.

Summary of Meta-analyses of Studies Considering Lesion Size Cut-off Thresholds for The Assessment of Eligibility for FNAB and Sonoelastography and Inter- and Intra-observer Agreement in Estimating the Malignant Potential of Focal Lesions of The Thyroid Gland.

Thyroid cancer is a tumour with a steadily increasing incidence. It accounts for 7% to 15% of focal lesions detected by ultrasound, depending on age, gender and other factors affecting its occurrence. Fine-needle aspiration biopsy is an essential method to establish the diagnosis but, in view of its limitations, sonoelastography is seen as a non-invasive technique useful in differentiating the nature of lesions and monitoring them after fine-needle aspiration biopsy. This paper presents a literature review on the role of both sonoelastographic techniques (relative strain sonoelastography, shear wave sonoelastography) to assess the deformability of focal thyroid lesions. Ultrasound examination is a relatively subjective method of thyroid imaging, depending on the skills of the examiner, the experience of the centre, and the quality of equipment used. As a consequence, there are inconsistencies between the results obtained by different examiners (inter-observer variability) and by the same examiner (intra-observer variability). In this paper, the authors present a review of the literature on inter-observer and intra-observer variability in the assessment of individual features of ultrasound imaging of focal lesions in the thyroid. In addition, the authors report on an analysis of cut-off thresholds for the size of lesions constituting the basis for fine-needle aspiration biopsy eligibility assessment. The need to diagnose carcinomas up to 10 mm in diameter is highlighted, however a more liberal approach is recommended in terms of indications for biopsy in lesions associated with a low risk of malignancy, where, based on consultations with patients, active ultrasound surveillance might even be considered.

Noninvasive follicular thyroid neoplasm with papillary-like nuclear features: a problematic entity.

Noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) is a borderline thyroid tumour formerly known as noninvasive encapsulated follicular variant of papillary thyroid carcinoma. The prevalence of NIFTP is estimated at 4.4-9.1% of all papillary thyroid carcinomas worldwide; however, the rate of occurrence of NIFTP is eight times lower in Asian countries than in Western Europe and America. At the molecular level, NIFTP is characterised by the lack of BRAF V600E and BRAF V600E-like mutations or other high-risk mutations (TERT, TP53), and a high rate of RAS mutations, which is similar to other follicular-pattern thyroid tumours. The diagnosis of NIFTP can only be made after histological examination of the entire tumour removed during surgery, and is based on strictly defined inclusion and exclusion criteria. Although the diagnosis is postoperative, the combination of certain findings of preoperative tests including ultrasonography, cytology, and molecular testing may raise suspicion of NIFTP. These tumours can be effectively treated by lobectomy, although total thyroidectomy remains an option for some patients. Radioactive iodine and thyroid stimulating hormone suppression therapy are not required. NIFTP has an extremely good prognosis, even when treated conservatively with lobectomy alone. Nevertheless, it cannot be considered as a benign lesion. The risk of adverse outcomes, including lymph node and distant metastases, is low but not negligible.

Does the TT Variant of the rs966423 Polymorphism in DIRC3 Affect the Stage and Clinical Course of Papillary Thyroid Cancer?

Thyroid cancer (TC) is the most common cancer of the endocrine system. Most new diagnoses are of low-grade papillary thyroid cancer (PTC), suggesting that PTC may be over-diagnosed. However, the incidence of advanced-stage PTC has increased in recent years. It is therefore very important to identify prognostic factors for advanced PTC. Somatic mutation of the BRAF gene at V600E, or the coexistence of the BRAF V600E mutation and mutations in the TERT promoter are associated with more aggressive disease. It would also be valuable to identify genetic risk factors affecting PTC prognosis. We therefore evaluated the impact of the rs966423 polymorphism in the DIRC3 gene, including its relationship with unfavorable histopathological and clinical features and mortality, in differentiated thyroid cancer (DTC). The study included 1466 patients diagnosed with DTC from one center. There was no significant association between the DIRC3 genotype at rs966423 (CC, CT, or TT) and any histopathological or clinic factor examined, including initial response to therapy, response at follow-up, or overall mortality, in DTC patients.