Which nodules should be biopsied to rule out malignancy?

Which nodules should be biopsied to rule out malignancy?

• A. Nodules >1.5 cm with normal TSH
• B. Nodules <0.5 cm
• C. Nodules with high TSH
• D. Nodules with low TSH

Answer: (A)

Evaluating thyroid nodules hinges on both size and thyroid function. The test used to rule out cancer is fine-needle aspiration biopsy, and you prioritize sampling for nodules that are large enough to carry meaningful cancer risk and that are not functionally hyperactive. When the thyroid is functioning normally, the cancer risk in a nodule increases with size, so a nodule about 1.5 cm or larger is typically biopsied to rule out malignancy. Very small nodules (less than about 0.5 cm) have a very low likelihood of cancer and are not biopsied because sampling is difficult and unlikely to change management. Nodules that are hyperfunctioning (low TSH) are usually benign hot nodules, so biopsy is not routinely indicated for cancer unless ultrasound features are suspicious. Nodules with high TSH can be nonfunctioning and still require assessment based on size and imaging features rather than TSH alone. So the combination of a relatively large nodule with a normal TSH signals enough concern to perform a biopsy to rule out malignancy.

Evaluating thyroid nodules hinges on both size and thyroid function. The test used to rule out cancer is fine-needle aspiration biopsy, and you prioritize sampling for nodules that are large enough to carry meaningful cancer risk and that are not functionally hyperactive.

When the thyroid is functioning normally, the cancer risk in a nodule increases with size, so a nodule about 1.5 cm or larger is typically biopsied to rule out malignancy. Very small nodules (less than about 0.5 cm) have a very low likelihood of cancer and are not biopsied because sampling is difficult and unlikely to change management. Nodules that are hyperfunctioning (low TSH) are usually benign hot nodules, so biopsy is not routinely indicated for cancer unless ultrasound features are suspicious. Nodules with high TSH can be nonfunctioning and still require assessment based on size and imaging features rather than TSH alone.

So the combination of a relatively large nodule with a normal TSH signals enough concern to perform a biopsy to rule out malignancy.