Repeat Fine-Needle Aspiration With Molecular Analysis in Management of Indeterminate Thyroid Nodules.

Objective: To analyze clinical outcomes in a series of indeterminate thyroid nodules (ITNs) with repeat fine-needle aspiration (FNA) biopsy and results of genomic classifier.

Study Design: Historical chart review.

Setting: Tertiary care center.

Methods: We reviewed FNA samples from subjects with Bethesda III or IV diagnoses from January 2015 to December 2018 at a single institution and selected those with repeat FNA and ThyroSeq testing of the same nodule. Patient demographics, Bethesda classifications, ThyroSeq results, treatment detail, and surgical pathology, when available, were analyzed.

Results: Ninety-six patients with cytologic diagnosis of ITN, repeat FNA, and ThyroSeq testing were identified. Following repeat FNA, 55 nodules (57%) remained ITN; 40 (42%) were reclassified as benign; and 1 (1%) was reclassified as suspicious for malignancy. In 31 patients with ThyroSeq analysis accompanying initial and repeat FNA, 26 (84%) had the same result on each, while 5 (16%) tested ThyroSeq positive following an initially negative result (κ = 0.24). Most nodules that were downgraded to Bethesda II on repeat FNA (37/40, 93%) were managed nonsurgically. Patients with ThyroSeq-positive results were treated with surgery more often (25/28, 89%) than patients with ThyroSeq-negative results (11/68, 16%; P < .0001). In excised nodules, the prevalence of malignancy and noninvasive follicular thyroid neoplasm with papillary-like nuclear features was 28% (n = 10) and 22% (n = 8), respectively, and all malignancies were low risk.

Conclusion: In this case series, repeat FNA helped patients with ITNs avoid diagnostic surgery through reclassification to benign cytology. The risk of high-risk malignancy in ThyroSeq-positive nodules with repeat indeterminate cytology was low.