Abstract

Back ground: BSFRTC is widely adopted in the management of the thyroid nodules. Post implementation experiences and the lessons learned from them is the subject of this short review.

Methods: Published experiences and appraisals post BSFRTC reviewed, focusing on the variation in reported ROM, state of Atypia of Undetermined Significance (AUS) category and the cytological diagnosis of Non-Invasive Follicular Neoplasm with Papillary like Nuclear Features (NIFTP) as well as the role of two key indicators, namely Risk of Neoplasia (RON) and surgical rates.

Results: The differences in ROM between the reported values and values expected by BSFRTC are due to variation in practice among institutions and it does not affect the performance of the schema. Using the total number of cases in the category as a dominator in the calculation of ROM shall reduce or even abolish the differences. Opinion about AUS varied between abolishing and merging it with SFN or maintaining it with further subcategorization. The consensus post BSFRTC 2017 is to keep the AUS category and stratified into different subgroups based on the type and degree of atypia. RON and the surgical follow-up rates are essential quality indicators. RON/ROM ratio could be utilized to determine the appropriate management for each diagnostic category on an institutional basis. A RON/ROM ratio close to unity in indeterminate categories is indicative for surgical triaging. The rate of surgery in different Bethesda group is an indication of how far clinicians accept the schema. NIFTP cannot be easily separable from other follicular lesions on cytology alone or combined with available molecular tests. Considering NIFTP benign, improve the stratification in ROM between indeterminate groups.

Conclusion: BSFRTC is an effective schema, well accepted by clinician, and has improved greatly the management of thyroid nodules. Maintaining AUS with sub categorization, considering NIFTP benign and calculating RON and surgical rates shall improve the performance of the schema.

Keywords: Revised Bethesda System for Reporting Thyroid Cytology (BSFRTC); Risk of Malignancy (ROM); AUS; Non-Invasive Follicular Tumor with Papillary like Nuclear Features (NIFTP)