From the Research
For a TI-RADS 4B thyroid nodule with benign FNA results, repeat ultrasound is recommended in 12 months, with consideration for a second follow-up ultrasound at 24 months. This recommendation is based on the most recent and highest quality study available, which suggests that the risk of malignancy in TI-RADS 4B nodules is moderate, and that repeat ultrasound can help identify any changes that may suggest malignant transformation 1. The follow-up ultrasound should assess for any changes in nodule size, echogenicity, margins, or vascularity that might suggest malignant transformation.
Some key points to consider when evaluating TI-RADS 4B thyroid nodules with benign FNA results include:
- The risk of malignancy in TI-RADS 4B nodules is moderate, ranging from 15-20% 2
- The false-negative rate of FNA is approximately 2-5%, which is particularly relevant for higher-risk TI-RADS categories 3
- Repeat ultrasound can help identify any changes that may suggest malignant transformation, and can provide reassurance if no changes are observed 1
- The American College of Radiology (ACR) Thyroid Imaging Reporting and Data System (TI-RADS) is a useful tool for evaluating thyroid nodules, and can help guide management decisions 4
Overall, the approach to managing TI-RADS 4B thyroid nodules with benign FNA results should balance the moderate suspicion for malignancy against the reassurance provided by the benign FNA result, and should take into account the individual patient's risk factors and clinical presentation. Repeat ultrasound at 12 months, with consideration for a second follow-up ultrasound at 24 months, is a reasonable approach, and can help identify any changes that may suggest malignant transformation, while also minimizing unnecessary testing and procedures 1.