The role of ThyroSeq V3 testing in the management of patients with indeterminate thyroid nodules on fine needle aspiration

BACKGROUND The multigene genomic classifier ThyroSeq V3 has proven to be an effective triage modality in the management of indeterminate thyroid nodules. This study reports on the clinical management of patients with indeterminate thyroid nodules. METHODS ThyroSeq V3 testing at our institution was implemented April 1, 2019. Over a 17-month period (1 April 2019 through 31 August 2020). Thirty five indeterminate thyroid nodules were sent for testing; diagnoses included FLUS, suspicious for a follicular/Hurthle cell neoplasm (SFN/SHCN) and suspicious for papillary thyroid carcinoma (SPTC). There were 26 females, nine males; mean age 56 years. Aspirated nodules, mean size of 2 cm, were evaluated by rapid on site evaluation with adequacy assessed by the cytopathologist via telecytology. RESULTS Of the 35 nodules, 17 (49%) were positive and 18 (51%) were negative on ThyroSeq Testing. All of the 17 positive nodules (four FLUS, 10 SFN/SHCN, three SPTC) showed neoplastic lesions; five adenomas, one NIFTP and 11 carcinomas on surgical resection. Only 4 (22%) of the 18 nodules that were negative were resected and showed two colloid/adenomatous nodules, one NIFTP and one follicular variant of papillary thyroid carcinoma. As FLUS FNAs were the majority of the indeterminate nodules, a comparison was made pre-and post ThyroSeq testing. Prior to ThyroSeq testing the majority (69%) of the nodules were resected as compared to 36% post implementation; a statistically significant value (P