Background: Fine Needle Aspiration (FNA) is a crucial diagnostic procedure in managing thyroid pathology. Increase in nodule size despite previous benign cytology often results in repeat FNA. We aim to evaluate the outcome of benign (Thy2 / Bethesda II) FNAs and identify predictive sonographic findings for malignancy in this group.
Methods: Retrospective review of radiologically guided thyroid FNAs in a single institute from 2019-2024. Follow up ultrasound, FNA results, and histology were evaluated.
Results: 394/680 (57.9%) had benign cytology. 212/394 (54.0%) underwent no further FNAs. 134/394 (34.0%) had a second benign FNA. 25/394 (6.3%) had subsequent Thy3a cytology (18/394 Thy3a AUS; 7/394 Thy3a FLUS). Of those with Thy2 cytology who underwent surgery 1/36 (2.8%) had malignant histology. 3/9 (33.3%) of those with subsequent Thy3a cytology who underwent surgery had malignant histology. In repeat benign FNAs, majority 100/134 (74.6%) had an increase in size >2mm with no other sonographic changes; 28/134 (20.9%) showed no radiological changes. No sonographic predictive factor of malignancy in those with repeat Thy3a FNA was identified.
Conclusion: In the absence of other radiological changes, an increase in nodule size alone in previous benign FNA is likely to yield a repeat benign result.
Nadia Van Den Berg1, Mohammad Altawil1, Julie McCarthy2, Patrick McLaughlin3, Patrick Sheahan1,4
1 Department of Otolaryngology, Head & Neck Surgery, South Infirmary Victoria University Hospital, Cork
2 Department of Pathology, Cork University Hospital, Cork
3 Department of Radiology, South Infirmary Victoria University Hospital, Cork
4 ENTO Research Unit, College of Medicine and Health, University College Cork, Cork