Endocrine Abstracts

First TBSRTC editions have made advances in problems of thyroid management. However, the real grey zone ‘AUS/FLUS’ and ‘FN/SFN’categories have been remained to be problematic with the wide range of ROMs documented in the literature alongside two editions. The ROMs of ‘AUS/FLUS’ and ‘FN/SFN’ categories were defined as 5-15% and 15-30% and the management was ‘repeat FNA’ and ‘lobectomy’ -respectively- in the first edition. Dual terminology, especially in ‘AUS/FLUS’ category referring different type of atypia: AUS -nuclear atypia- and FLUS -pattern atypia- together with the indication of ‘either AUS or FLUS would be selected by a laboratory because they are synonymous’ was enough to lead to a confusion and create a waste-basket category. 2 nd edition tailored to prevent the overuse of this category and patient management of AUS/FLUS category offered molecular testing beside the choice of repeat FNA. During these two editions the literature have been continued to represent higher ROMs than TBSRTC suggested and studies with the suggestion of subcategorization for those categories were increased. Following the perplexity of the indetermined categories, the 3 rd edition of TBSRTC finally offered a subcategorization to these categories and ‘AUS/FLUS’ category will be divided into ‘AUS-nuclear atypia’ and ‘AUS, other’ and ‘FN/SFN’ category will be divided into ‘SFN (non-oncocytic)’ and ‘SFN-oncocytic’. This is a retrospective study of patients with surgery and FNA dates between 2009 and 2019, and whose nodules were cytologically diagnosed as AUS or SFN according to TBSRTC-2017. The following data was noted for each subject: Patients’ age and sex, the type of surgery, the number of nodules evaluated for each patient, the nodule sizes, cytological and histological diagnoses of the nodules and ROMs for each cytological categories and subcategories. Statistical analysis is made on PASW Statistics 18.0.0. Chi-square was used to correlate 2nd and 3rd Bethesda categories/subcategories with surgical outcomes and ROMs. Histopathological examination was performed on total thyroidectomy 91 and on lobectomy 9%. 203 nodules had size information, and mean size was 28,2 (8-68) mm.Of these nodules,31%were diagnosed as AUS and 69% were diagnosed as SFN in their FNA. Surgery revealed 23CLT(chronic lymphocytic thyroiditis), 38 BFN (benign follicular nodule), 56 FA (follicular adenoma), 26 AO (oncocytic adenoma),2WDT-UMP(well differentiated tumor uncertain malignant potential), 4 NIFT-P, 97PTC(papillary thyroid carcinoma), 2 FTC(folicular thyroid carcinoma)and 4 OC(oncocytic carcinoma) cases. Both division based on oncocytic features and subdivision based on PTC nuclear features showed high significance (P < 0,001) for histological diagnoses of the nodules. Similarly in terms of ROMs, division based on oncocytic features showed high significance (P = 0,015) and subdivision based on PTC nuclear features showed even higher concordance (P < 0,001) ROMs of SFN category and its subcategories.