Should a 2-centimeter (cm) thyroid nodule with no change after 5 years be biopsied?

From the Guidelines

A thyroid nodule that has remained stable in size for 5 years generally does not require a biopsy, even if it initially appeared suspicious. This recommendation is based on the understanding that thyroid nodules that are truly malignant typically show growth over time, so stability over a 5-year period is reassuring 1. However, this assumes there are no other concerning features that have developed or changed. Key factors to consider include:

• Suspicious ultrasound characteristics such as irregular margins, microcalcifications, hypoechogenicity, or increased vascularity
• Risk factors like family history of thyroid cancer or history of radiation exposure to the neck
• New symptoms such as difficulty swallowing, voice changes, or enlarging lymph nodes

If any of these factors are present, a biopsy might still be warranted despite the stability of the nodule's size. The decision should ultimately be made in consultation with an endocrinologist who can evaluate the complete clinical picture, including the original reason the nodule was deemed suspicious and any changes in the patient's overall health status. It's also important to note that the majority of thyroid nodules are benign, and the overdiagnosis of thyroid cancer, particularly small papillary carcinomas, is a significant concern 1. Therefore, a cautious approach, balancing the risk of missing a malignancy against the risks and costs of unnecessary biopsies and treatments, is prudent.

From the Research

Thyroid Nodule Biopsy Considerations

• The decision to biopsy a thyroid nodule is typically based on its size, appearance, and other clinical factors, rather than the duration of its presence 2, 3, 4.
• A 2cm thyroid nodule is considered relatively large and may warrant biopsy, regardless of its stability over time 2, 5.
• Fine-needle aspiration biopsy (FNA) is the standard test for evaluating thyroid nodules and determining the need for surgical removal 2, 3, 4, 5, 6.
• The accuracy of FNA biopsy approaches 95%, making it a reliable method for distinguishing between benign and malignant nodules 3, 4.

Factors Influencing Biopsy Decision

• The presence of suspicious ultrasound features or clinical findings suggestive of malignancy may prompt biopsy, even if the nodule is stable in size 5, 6.
• The American College of Endocrinology and other organizations have established guidelines for the evaluation and management of thyroid nodules, which may recommend biopsy for nodules of a certain size or with specific characteristics 2, 4.
• The use of ultrasound-guided FNA biopsy can improve the accuracy of the procedure and reduce the risk of nondiagnostic or false-negative results 6.

Clinical Implications

• If a biopsy is performed and the results are benign, careful clinical follow-up is recommended to monitor for any changes in the nodule's size or appearance 3, 4.
• If the biopsy results are suspicious or malignant, surgical excision of the nodule may be necessary 3, 5.
• The management of thyroid nodules should be individualized, taking into account the patient's overall health, medical history, and other relevant factors 2, 4, 5.