The Role of Repeat Fine Needle Aspiration in Improving Diagnostic Accuracy in Thyroid Masses 1Laura Allen, 2Ayham Al Afif, 2Matthew H Rigby, 3Martin J Bullock, 2Jonathan Trites, 2S Mark Taylor, 2Robert D Hart 1Faculty of Medicine, 2Division of Otolaryngology – Head & Neck Surgery, 3Department of Pathology, Dalhousie University, Halifax, NS Introduction Results Background Fine needle aspiration (FNA) is an important tool in diagnosing thyroid masses. The Bethesda System for Reporting Thyroid Cytopathology (BSRTC) recommends repeat FNA (rFNA) when initial FNA results are unsatisfactory (Category I), Atypia of Undetermined Significance/Follicular Lesion of Undetermined Significance (AUS/FLUS) (Category III) 1. It is unclear how often rFNA provides further diagnostic information1-5. malignant n=4 (2%) malignant n=4 (9%) benign n=13 (30%) SFN/SFM n=3 (2%) Conclusions Table I. BSRTC Categories Our study suggests that rFNA may have a role in providing diagnostic information following indeterminate FNA cytology. Future directions include obtaining a larger sample size to clarify the impact of rFNA on clinical decision making. Objectives Does repeat FNA following indeterminate initial cytology improve diagnostic accuracy in patients with thyroid masses? Methods Summary Acknowledgements Department of Otolaryngology & Dr. Gerry Johnston – Dr. James S. Hammerling Summer Research Studentship Retrospective chart review (n=237) patients Patients: Male & Female, >18 years, Unsatisfactory or AUS/FLUS on initial FNA cytology at the QEII HSC between 2013-2015 Exclusion criteria: FNA done before 2013, no rFNA performed 1st FNA pathology: Unsatisfactory (n=194) AUS/FLUS (n=43) rFNA pathology: Unsatisfactory (n=78) AUS/FLUS (n=64) Benign (n=84) Malignant (n=8) Abnormal (n=3) Demographic data: Patient Age, Sex Surgical outcome: surgery (n =63), no surgery (n=174) Data analysis: Frequencies of rFNA contributing to a new or changed diagnosis Key findings rFNA following an initial unsatisfactory FNA provided a new diagnosis in 65% of patients. 39% of patients with initial AUS/FLUS cytology had a definitive diagnosis on rFNA (benign or malignant). In total, 36% of patients who had rFNA underwent surgery. Of those patients with a result of AUS/FLUS on rFNA, 15% underwent surgery. Of those patients who had both initial and rFNA results of Unsatisfactory, 25% had surgery. References Cibas, E. S., & Ali, S. Z. (2009). The Bethesda system for reporting thyroid cytopathology. American journal of clinical pathology, 132(5), 658-665. Gerhard, R., & Boerner, S. L. (2015). Evaluation of Indeterminate Thyroid Cytology by Second-Opinion Diagnosis or Repeat Fine-Needle Aspiration: Which Is the Best Approach. Acta cytologica, 59(1), 43-50. Na, D. G., Kim, J. H., Sung, J. Y., Baek, J. H., Jung, K. C., Lee, H., & Yoo, H. (2012). Core-needle biopsy is more useful than repeat fine-needle aspiration in thyroid nodules read as nondiagnostic or atypia of undetermined significance by the Bethesda system for reporting thyroid cytopathology.Thyroid, 22(5), 468-475. Chen, J. C., Pace, S. C., Chen, B. A., Khiyami, A., & McHenry, C. R. (2012). Yield of repeat fine-needle aspiration biopsy and rate of malignancy in patients with atypia or follicular lesion of undetermined significance: the impact of the Bethesda System for Reporting Thyroid Cytopathology.Surgery, 152(6), 1037-1044. Key points rFNA following indeterminate cytology (Unsatisfactory or AUS/FLUS) of thyroid mass may play a role in providing more definitive diagnostic information. The impact of rFNA on clinical/surgical outcomes remains unknown. Contact Laura Allen, BHSc. MD Candidate 2019 laura.allen@dal.ca