Impact of the bethesda system for reporting thyroid cytology in the Illawarra Shoalhaven regions of NSW

Aim To investigate the impact of the Bethesda classification on reporting of thyroid fine needle aspiration (FNA) biopsies in our practice. Method Thyroid FNA cases from 2008 to August 2012 were retrieved from the computer files of Southern IML and the Wollon-gong Hospital, where most of the cytology and histology cases in the Illawarra/Shoalhaven regions of NSW are reported. The first half of 2008 (before the Bethesda system was published) was compared to the second half of 2011, after the Bethesda system was formally adopted in our practice. Results We analysed 150 cases pre-Bethesda (1.1.08–31.5.08) and 361 cases post-Bethesda (1.5.11–31.12.11). Cases from 2008 and 2011 were classified as follows: insufficient (25.3% vs 16.9%), benign (66% vs 73%), atypical (4% vs 4.4%), atypical follicular pattern/follicular neoplasm (4% vs 1.9%), suspicious for malignancy (0.7% vs 0.8%), malignant (0 vs 1.1%). Discussion In our practice, use of the Bethesda System for Reporting Thyroid Cytology has improved consistency of reporting by providing standardised criteria which was reflected in the pathology reports. The increased numbers of benign cases is consistent with change in ultrasound biopsy practices (re-flected in the different population characteristics) and current literature.