Endocrine Abstracts

Background: Autonomic hyperfunctioning thyroid nodules account for approximately 5% to 10% of all thyroid nodules. Compared with non-toxic nodules, hot nodules are traditionally believed to have an exceptionally low malignancy rate, and this has led to recommendations not to perform fine-needle aspiration (FNA) on these lesions, regardless of their size. However, recent studies have questioned the presumed low risk of malignancy in hot nodules, suggesting that the incidence of cancer has been underestimated and the need for further studies to provide more evidence in this regard.

Aims: 1) To assess the prevalence of differentiated thyroid carcinoma (DTC) in the definitive histological examination in patients who underwent total thyroidectomy or hemithyroidectomy due to unique toxic nodules in a tertiary hospital. 2) To verify the existence of ultrasound predictors of malignancy on toxic nodules.

Methods: Retrospective descriptive study. Inclusion criteria: gammagraphically unique hot nodules from 2006 to 2021. Exclusion criteria: toxic multinodular goiters. Demographic data, performance or not of FNA, ultrasound characteristics of the nodules and thyroid function record at diagnosis were analyzed.

Results: The ultrasound classification by ACR TI-RADS of the remaining 68 benign nodules was: 1.5% TR1, 20.6% TR2, 20.6% TR3, 28% TR4, 1.5% TR5 and 28% unknown.

Conclusions: The prevalence of malignancy on the operated nodules was 4.2% (slightly lower than that described in the literature for non-toxic nodules). Higher scores in the malignancy risk scales on solitary toxic nodules could suggest the need to perform FNA on them.