What diagnostic procedure is indicated for palpable thyroid masses with a normal TSH concentration?

For a palpable thyroid mass with a normal TSH concentration, the most appropriate diagnostic procedure is fine-needle aspiration biopsy. This method is crucial in the evaluation of thyroid nodules, particularly when there are concerns about the potential for malignancy.

Fine-needle aspiration biopsy is a minimally invasive procedure that involves using a thin needle to extract cells from the thyroid nodule. These cells are then examined histologically to determine whether the nodule is benign or malignant. The procedure is favored in this context because it provides a reliable way to obtain cellular material for cytological evaluation, allowing for early detection of thyroid cancer.

In cases where there is a normal TSH level, it indicates that the function of the thyroid gland is normal, but it does not eliminate the possibility of malignancy in a palpable mass. Therefore, obtaining a definitive diagnosis through a fine-needle aspiration biopsy is warranted to appropriately guide management.

Other imaging modalities like ultrasonography, CT scans, or MRI can provide additional information about the characteristics of the thyroid mass, but they do not provide a definitive diagnosis. Specifically, while ultrasonography is useful for guiding the biopsy and assessing the nodule size and features, it is not a definitive diagnostic procedure on its own. CT and MRI are