Discussion of “The presence of papillary features in thyroid nodules diagnosed as atypia of undetermined significance or follicular lesion of undetermined significance increases cancer risk and should influence treatment”

Abstract

I would like to congratulate the authors on reviewing their institutional experience in a manner that is clinically relevant and should improve the care delivered to patients who fall into this category of thyroid nodules. As described in the manuscript there are lots of thyroid nodules present in the population. In speaking with our radiologist, they actually take pause and think about the downstream effect for the patient of mentioning findings in the thyroid. As such, I suspect there are even more thyroid nodules seen on imaging than reported. Although there are lots of nodules the vast majority will be benign but it is up to us to figure out with the least fuss which ones are significant and to do that with the least intervention. I have several questions for the authors. 1You reported 504 thyroid FNA's of which 64 were repeat biopsies that were excluded in your evaluation. How many of the AUS with papillary features had repeat biopsies at 3 months as suggested by current guidelines? If there were a significant number that had repeat biopsies how will your current findings of AUS with papillary features having a 47% ROM impact clinical management for this group. 2It is interesting that the ROM in your institution for AUS/FLUS was 32%. This is being reported out now by several other groups. 1 Nagarkatti S. Faquin W. Lubitz W. et al. The management of thyroid nodues with atypia on fine needle aspiration. Ann Surg Onc. 2013 January; 20https://doi.org/10.1245/s10434-012-2601-2 Crossref PubMed Scopus (66) Google Scholar Why do you think several groups are now finding rates higher than expected based on data looked at to develop the Bethesda criteria. Do you believe that interpretation of thyroid cytopathology has improved since standardization with the Bethesda criteria and far less benign lesions are being signed out as AUS/FLUS thereby decreasing the denominator ? Have you found that your pathology department has gotten better at categorizing these lesions and hence the better correlation with risk of malignancy. 3In the manuscript you discuss the category of Non Invasive Follicular Thyroid Neoplasm with papillary features that will now no longer be considered malignant. There were cases of this in the AUS/FLUS group. This is great as it prevents over treatment for patients but do you think this will practically change the indications for surgical biopsy in this category. 4That brings me to the last question. Molecular evaluation of thyroid cytology looking a genetic changes like KRAS, BRAF, RET/PTC etc. to try to categorize benign from malignant with the goal being to perform less surgery for benign disease is also mentioned in the discussion. Did any of the patients in this study have genomic evaluation of cytology performed? Would love your thoughts on how this may potentially change clinical management in the future.