Growth of Benign Thyroid Nodules Is Associated With a High Reintervention Rate Without Clear Benefit

The American Thyroid Association (ATA) guidelines recommend routine follow-up ultrasounds following benign thyroid biopsies and repeat fine needle aspiration (FNA) biopsy for nodules that grow. We hypothesized that this may be associated with frequent reintervention without detecting additional cancers.

A single-center retrospective study of patients with an initial benign thyroid FNA from 2017 to 2021 was performed, 12 mo of data were randomly selected for review. The primary outcome of interest was the rate of repeat FNA or surgery (reintervention), and the secondary outcome of interest was the number of subsequent surveillance ultrasounds. Multivariable regression was used to identify preditors of reintervention.

A total of 411 patients with 562 biopsy-proven benign nodules were included. In total, 70 patients (17.1%) underwent at least one repeat biopsy, and 15 patients (3.9%) underwent thyroid surgery. Two patients (0.5%) were ultimately diagnosed with thyroid cancer, neither in the biopsied nodule. During a median follow-up period of 26.4 mo, 282 (68.6%) had at least one follow-up ultrasound, while 64 (15.6%) underwent five or more follow-up ultrasounds. At 5 y, nearly one-third of patients still under surveillance had undergone either repeat FNA or surgery. Patients with nodules meeting ATA growth criteria for repeat FNA were more likely to undergo repeat biopsy than those whose nodules did not (48.5% versus 23.5%, P = 0.02).

Malignancy after an initial benign thyroid FNA biopsy is rare, and subsequent surveillance is resource-intensive without clear benefit. The growth criteria for repeat FNA in the 2015 ATA guidelines were associated with reintervention without detection of malignancies.