What should I do about a thyroid nodule on ultrasound with a normal Thyroid-Stimulating Hormone (TSH) level

From the Guidelines

If you have a thyroid nodule on ultrasound with a normal TSH level, you should follow up with an endocrinologist or your primary care physician for further evaluation, as the majority of thyroid nodules are benign, but a small percentage can be cancerous 1. When evaluating a thyroid nodule, it's essential to consider the nodule's characteristics on ultrasound to determine its risk level.

• Nodules larger than 1 cm, those with suspicious features (irregular margins, microcalcifications, increased vascularity), or nodules in someone with risk factors like radiation exposure or family history of thyroid cancer may require a fine needle aspiration biopsy 1.
• Even with normal thyroid function (normal TSH), nodules can still potentially be cancerous, though most (about 90-95%) are benign 1.
• Your doctor might recommend periodic ultrasound monitoring for smaller, non-suspicious nodules, typically every 6-12 months initially, then less frequently if stable.
• It's also important to note that thyroid nodules are common, affecting up to 50% of adults, and the vast majority are not dangerous 1.
• A normal TSH is reassuring that the nodule isn't producing excess thyroid hormone, but it doesn't rule out the need for structural evaluation of the nodule itself 1. The American College of Radiology (ACR) has published guidelines for the management of thyroid nodules, including the use of ultrasound and fine needle aspiration biopsy 1.
• The ACR guidelines recommend a coordinated approach to the evaluation and management of thyroid nodules, taking into account the nodule's size, characteristics, and the patient's risk factors 1.
• The guidelines also emphasize the importance of avoiding unnecessary biopsies and surgeries, as the majority of thyroid nodules are benign 1.
• A recent study published in 2025 highlights the complexity in the interpretation and application of multiple guidelines for thyroid nodules, emphasizing the need for coordinated recommendations for "small" lesions 1.

From the Research

Thyroid Nodule Evaluation

If you have a thyroid nodule on ultrasound with a normal Thyroid-Stimulating Hormone (TSH) level, the following steps can be considered:

• Most thyroid nodules are benign, and a surveillance program can be safely managed [ 2 ].
• The main goal of initial and long-term follow-up is to identify the small subgroup of nodules that harbor a clinically significant cancer, cause compressive symptoms, or progress to functional disease [ 2 ].

Ultrasound Characteristics

Certain ultrasound features can guide the initial management of thyroid nodules:

• A cystic or spongiform appearance suggests a benign process that does not require additional testing [ 2 ].
• Suspicious sonographic patterns, including solid composition, hypoechogenicity, irregular margins, and microcalcifications, should prompt cytological evaluation [ 2 ].

Fine-Needle Aspiration Biopsy (FNAB)

FNAB remains crucial in the evaluation of thyroid nodules with suspicious clinical findings or ultrasound features suggestive of malignancy:

• The use of ultrasound-guidance for FNAB allows real-time visualization of the needle and can lower the yield of nondiagnostic specimens and false-negative results [ 3 ].
• A standardized and meticulous technique for US-FNAB is essential for increasing the diagnostic results [ 3 ].

Management

Management of thyroid nodules includes:

• Simple observation [ 2 ].
• Local treatments [ 2 ].
• Surgery, which should be based on the estimated risk of malignancy and the presence and severity of compressive symptoms [ 2 ].
• A diagnostic approach that uses ultrasound and, when indicated, fine-needle aspiration biopsy and molecular testing, facilitates a personalized, risk-based protocol that promotes high-quality care and minimizes cost and unnecessary testing [ 2 ].

Quality of Evaluations

There is great variation in the quality of thyroid nodule evaluations before surgical referral:

• Obtaining a TSH value and an ultrasound with enough information to risk stratify the nodule are necessary components of thyroid nodule evaluations [ 4 ].
• Only 51.5% of evaluations included both a TSH and a thyroid ultrasound, and 9.4% of the entire cohort received a guideline-concordant, high-quality evaluation [ 4 ].