From the Guidelines
For a thyroid nodule with a TIRADS 5 score and a previously normal biopsy result that appears stable on ultrasound, follow-up is recommended every 6-12 months with ultrasound for at least 2-3 years, then annually thereafter if stability continues. This recommendation is based on the most recent and highest quality study available, which emphasizes the importance of vigilant monitoring for TIRADS 5 nodules due to their higher risk of malignancy (>20%) 1. Despite the initial benign biopsy, the suspicious sonographic features of TIRADS 5 nodules, such as irregular margins, microcalcifications, or marked hypoechogenicity, necessitate regular follow-up to detect any potential changes or growth. The American College of Radiology (ACR) also supports the use of ultrasound for monitoring thyroid nodules, highlighting its key role in diagnosing and characterizing thyroid findings for management 1.
Some key points to consider in the follow-up of TIRADS 5 nodules include:
- False-negative results can occur in approximately 2-5% of fine needle aspiration biopsies, making regular monitoring essential 1.
- Concerning changes during follow-up, such as nodule growth (>20% increase in two dimensions with a minimum 2mm increase), development of suspicious lymph nodes, or new suspicious sonographic features, should prompt a repeat biopsy.
- Some clinicians may consider a repeat biopsy after 12 months even without changes, particularly for highly suspicious nodules, to further confirm the benign nature of the nodule.
- The Thyroid Imaging Reporting And Data Systems (TIRADS) have emerged as crucial tools for risk stratification of thyroid nodules detected on ultrasound, and their use can help minimize unnecessary fine needle aspiration (FNA) 1.
Overall, a balanced approach that acknowledges both the reassurance of the initial benign result and the higher risk profile suggested by the TIRADS 5 classification is necessary for the management of these nodules. Regular follow-up with ultrasound, as recommended, can help detect any potential changes or growth, ultimately prioritizing the patient's morbidity, mortality, and quality of life.
From the Research
Thyroid Nodule Follow-Up
- A thyroid nodule with a TIRAD score of 5 and a previously normal biopsy result, given a stable thyroid ultrasound, requires careful monitoring.
- According to the study by 2, long-term follow-up of benign thyroid nodules is associated with increased repeat fine-needle aspiration (FNA) and ultrasound without improvement in the malignancy detection rate.
- The same study suggests that after 3 years of follow-up, consideration should be given to ceasing long-term routine follow-up of biopsy-proven benign colloid nodules (BCN).
- However, the study by 3 recommends follow-up of benign thyroid nodules confirmed by ultrasound-guided core needle biopsy after inconclusive cytology on fine-needle aspiration biopsy, with a median follow-up period of 27.5 months.
Recommended Follow-Up Interval
- The American College of Radiology Thyroid Imaging Reporting and Data System committee published a standardized approach to classifying nodules on ultrasound, as mentioned in the study by 4.
- Although there is no specific recommendation for a TIRAD score of 5, the study by 5 defines TIRADS 5 as having a >80% malignancy risk.
- Given the high risk of malignancy associated with a TIRAD score of 5, it is reasonable to consider a shorter follow-up interval, such as 6-12 months, to monitor for any changes in the nodule's size or characteristics, as suggested by the study by 6.
- However, the optimal follow-up interval may vary depending on individual patient factors and clinical judgment, and should be determined in consultation with a healthcare provider.