Endocrine Abstracts

Objectives: The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) is a validated and widely used tool for thyroid nodules triage. Studies reporting on the frequency of each Bethesda category are scarce, and there are wide discrepancies in the reported results between the various centers. Our aim was to register all cytological reports of the thyroid fine needle aspiration biopsies (FNAB) reviewed in the Cytology Department of a tertiary hospital during a calendar year, and to compare them with the literature and the TBSRTC recommendations.

Methods: We reviewed 448 reports of thyroid FNAB performed under ultrasound guidance and reported at the Cytology Department of the University Hospital of Patras from 1/1 to 31/12/2022.

Results: Table 1 shows the percentages of each TBSRTC category in all FNAB samples examined, in those reported by the most experienced cytologist and in those reported by all other cytologists, the percentages reported in the literature and the expected percentages according to the TBSRTC recommendations. In the samples examined by the most experienced cytologist, there were significantly less reports of categories I and III, and significantly more reports of category II. Of the 30 patients with category III FNAB, thyroidectomy was recommended to 5 due to TIRADS V sonographic appearance of their nodules (3 surgeries done so far: 2 papillary carcinomas, 1 follicular tumor of uncertain malignant potential), and repeat FNAB was recommended to the rest.

Conclusions: The percentages of cytological diagnoses in thyroid FNAB material per TBSRTC category in our center were similar to the expected according to the TBSRTC recommendations. Increased experience of the reporting cytologist was associated with more Bethesda II and less Bethesda I and III reports.