The current study compares data from our hospital system before and after the 2008 implementation of the Bethesda System for Reporting Thyroid Cytology (BSRTC).
To show the effects the BSRTC has had on the reporting rates and outcomes for thyroid lesions.
A search for thyroid fine-needle aspiration biopsies (FNABs) was performed for 2002-2005 (before BSRTC) and 2009-2011 (after BSRTC). Diagnostic outcomes were reviewed for cases with available follow-up.
For 2002-2005, cytology reports for 3302 thyroid FNABs were reviewed, and 309 (9.4%) were classified as suspicious. For 2009-2011, cytology reports for 3432 thyroid FNABs were reviewed; 72 (2.1%) were classified as "atypia of undetermined significance or follicular lesion of undetermined significance" (AUS/FLUS), and 142 (4.1%) were classified as suspicious. Follow-up material was available for 31 AUS/FLUS cases (43.0%), and 6 of these cases (19%) were malignant. Follow-up material was available for 60 cases (42.3%) classified as suspicious, and 23 of these cases (38%) were malignant.
The AUS/FLUS rate of 2.1% at our institution is at the lower range of the <7% recommended by the BSRTC, and our rate of 19% for risk of malignancy for AUS/FLUS is slightly above the BSRTC recommendation of 5% to 15%. Implementation of the BSRTC did not significantly affect our institution's reporting rates, most likely because an essentially similar classification system was employed before implementation of the BSRTC.