In this report, we have summarized our 15-year experience, with comparison to the BSRTC and an emphasis on the cytologic-histologic correlation.
In November 2011, our institution modified its reporting categories to include the BSRTC category with a best fit to the categories that had been in use.
We used the best-fit approach to extract data and reclassify cases, mostly for the works published prior to the publication of BSRTC.
Table 1 shows the distribution of diagnoses before and after the inclusion of the BSRTC category, with the descriptive diagnosis for each FNA.
At our institution, Hurthle cell lesion/ neoplasm has always been considered a distinct category, and although indicated as BSRTC SFN/FN (IV), it is presented in Table 1 as a separate line category.
Similarly, "Suspicious for papillary carcinoma" had always been considered by us as a separate category, and it is presented as a BSRTC category V lesion, "Suspicious for malignancy.
Diagnoses were then reported in the 6-tiered BSRTC terminology for the 2009-2011 cases, and in a 4-tiered system for the 2002-2005 cases.
For 2002-2005, a total of 3302 thyroid FNABs were performed in our hospital system prior to implementation of the current BSRTC.
For 2009-2011, a total of 3432 thyroid FNABs were performed in our hospital system following the implementation of the current BSRTC in mid-2008.
20) A comparison of the data from our laboratory was then made with similar recently published results from other laboratories using the BSRTC.
The AUS/FLUS category has been a controversial category since the BSRTC was published in 2008.
Because our risks of malignancy for "suspicious for follicular neoplasm" and "suspicious for Hurthle cell neoplasm" were within the 15% to 30% recommended by the BSRTC, and our risk of malignancy for "suspicious for malignancy" was only slightly higher than the 60% to 75% recommended by the BSRTC, we believe that our use of the AUS/FLUS category was appropriate and only slightly at risk of being underused.