OBJECTIVES

To estimate the risk of malignancy in indeterminate thyroid nodules and to determine whether certain clinical or radiological parameters can predict the risk of malignancy.

METHODS

This retrospective study enrolled all adult patients (age ≥14 years) with a cytological diagnosis of atypia/follicular lesion of undetermined significance and follicular neoplasm/suspicious for a follicular neoplasm between January 2014 and January 2020. Fifty patients with surgically treated primary thyroid nodules, documented final histological diagnosis, and ultrasound examination records were included. Thyroid nodules were evaluated radiologically using Thyroid Imaging Reporting and Data System introduced by the American College of Radiology (2017).

RESULTS

Forty-two (84.0%) female and 8 (16.0%) male patients were enrolled in the study. The malignancy risks were 44.8% for Bethesda III and 28.6% for Bethesda IV. The malignancy risks for the Thyroid Imaging Reporting and Data System categories were 33.3% (TR2), 39.1% (TR3), 35.3% (TR4), and 50% (TR5). No significant associations were observed between age, gender, Bethesda category, and Thyroid Imaging Reporting and Data System and the risk of malignancy.

CONCLUSION

None of the clinical or radiological characteristics evaluated in this study contributed to the cancer risk stratification of thyroid nodules with indeterminate cytology. A prospective multicenter study is needed to better understand cytologically indeterminate thyroid nodules.