Does a patient with newly diagnosed Hashimoto's thyroiditis (Hashimoto's) require a thyroid ultrasound?

From the Guidelines

A newly diagnosed patient with Hashimoto's thyroiditis should generally have an ultrasound of the thyroid to evaluate the structure of the thyroid gland, detect nodules, and establish a baseline for future comparison. This recommendation is based on the importance of identifying any potential nodules that may require further evaluation through fine-needle aspiration, as patients with Hashimoto's have a slightly increased risk of thyroid cancer compared to the general population 1. The ultrasound is a non-invasive, painless test that does not involve radiation exposure and can help identify characteristic changes in Hashimoto's, including heterogeneous echogenicity, hypoechogenicity, and sometimes a pseudonodular pattern.

Some key points to consider when evaluating a patient with Hashimoto's thyroiditis include:

• The presence of a thyroid nodule, which can be detected by palpation or neck ultrasound 1
• The size and ultrasound characteristics of the nodule, which can help determine the likelihood of malignancy 1
• The patient's age, gender, and family history, which can also affect the probability of malignancy 1
• The presence of suspicious findings detected with imaging, such as focal 18-fluorodeoxyglucose (FDG) uptake on PET, or central hypervascularity, irregular border, and/or microcalcifications on ultrasound 1

Overall, the use of ultrasound in the evaluation of Hashimoto's thyroiditis is an important tool for identifying potential nodules and establishing a baseline for future comparison, and can help guide further evaluation and management as needed. The most recent and highest quality study supports the use of ultrasound in the initial evaluation of patients with Hashimoto's thyroiditis 1.

From the Research

Thyroid Ultrasound in Hashimoto's Thyroiditis

• A patient with newly diagnosed Hashimoto's thyroiditis may require a thyroid ultrasound to assess the degree of autoimmune destruction of the thyroid and to guide therapeutic decisions 2.
• Ultrasonography is a useful and essential tool in the diagnosis of Hashimoto's thyroiditis, and can help distinguish it from other thyroid disorders 3.
• Thyroid ultrasound can be used to detect nodules and assess their risk of malignancy, which is important in patients with Hashimoto's thyroiditis as they are at increased risk of developing thyroid neoplasms 4, 5.
• Various ultrasound-based malignant risk stratification systems, such as the American Thyroid Association (ATA), Korean Society of Thyroid Radiology (KSThR), and American College of Radiology (ACR) guidelines, can be used to assess thyroid nodules in patients with Hashimoto's thyroiditis 6.
• The ACR guidelines may be more effective in reducing unnecessary fine-needle aspiration biopsies in patients with Hashimoto's thyroiditis, especially in those with intermediate suspicion nodules 6.

Indications for Thyroid Ultrasound

• Thyroid ultrasound may be indicated in patients with Hashimoto's thyroiditis who have nodules or suspicious ultrasound findings 4, 5.
• Ultrasound-guided fine-needle aspiration biopsy may be necessary to differentiate between benign and malignant diseases in patients with Hashimoto's thyroiditis and thyroid nodules 5.
• Thyroid ultrasound can be used to monitor changes in thyroid function and anatomy over time, and to assess the response to treatment 2.

Limitations and Considerations

• The use of thyroid ultrasound in patients with Hashimoto's thyroiditis should be guided by clinical judgment and individual patient factors, rather than relying solely on ultrasound findings 2, 4.
• The interpretation of thyroid ultrasound findings should take into account the patient's clinical history, laboratory results, and other diagnostic tests 3, 5.