Thyroid FNA cytology: Impact of the COVID-19 pandemic and vaccination in a Brazilian series.

Background: The coronavirus disease 2019 pandemic prompted changes in medical practice, with a reduction in cytopathology volumes and a relative increase in the malignancy rate during lockdown and the initial postlockdown period. To date, no study has evaluated the impact of these changes on the volume of rapid on-site evaluation (ROSE) or on the frequency of cases according to The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) categories after vaccination.

Methods: Ultrasound-guided thyroid fine-needle aspiration (FNA) and ROSE assessments performed from January 2019 to May 2022 were evaluated retrospectively according to TBSRTC categories for three periods: prepandemic (period 1), from transmission to expansion (period 2), and after vaccination (period 3).