Ultrasonography in the Management of Thyroid Nodules FREE

The thyroid gland is located in the neck. It makes thyroid hormone, a substance that helps to regulate the body's use of energy. Thyroid nodules are lumps in the normally smooth thyroid. Thyroid nodules are very common. The first step in evaluating a nodule is a blood test to check thyroid hormone levels. If thyroid hormone levels are normal, then the doctor must consider other explanations for the nodule. While most nodules are not serious, a nodule 1 centimeter in size or larger in a patient with normal levels of thyroid hormone can be a sign of thyroid cancer. In such cases, further evaluation is needed. To see if a nodule is cancer, a needle is inserted into the nodule to get a sample to be examined under a microscope (fine-needle aspiration). Ultrasonography uses sound waves to create pictures of the body. Many doctors order ultrasonography when they feel a thyroid nodule, but the usefulness of this practice for all patients with thyroid nodules is unknown.

To determine whether routine ultrasonography tests help in the evaluation of thyroid nodules that are felt on physical examination.

223 patients referred to the thyroid clinic at a teaching hospital in Boston, Massachusetts, between October 1995 and March 1997.

The researchers collected information about patients' physical examinations and test results. This clinic did ultrasonography for all patients who had a nodule.

Of the 223 patients, 173 were sent to the clinic because of an abnormal thyroid examination and normal thyroid hormone levels. Of these 173 patients, 114 were thought to have a single nodule on examination and 59 were thought to have a generally enlarged thyroid (goiter). Ultrasonography results were useful in the evaluation of 109 of these 173 patients (63%). For 50 of the 114 patients referred because of a single nodule, ultrasonography showed one of two things: additional nodules at least 1 centimeter in size not felt on examination, or no nodules this large despite a physical examination that suggested otherwise. Among the 59 patients who were referred to the clinic because of an enlarged thyroid, 39 had ultrasonography examinations that showed nodules large enough to require fine-needle aspiration.

This study involved a single practice. The results might be different in other practices in which doctors' thyroid examination skills are different.

Ultrasonography tests appear useful for patients with abnormal thyroid examinations and normal thyroid hormone levels. Ultrasonography can find nodules at least 1 centimeter in size that cannot be felt on examination in some patients. In other patients, it shows no large nodules despite a physical examination that suggests otherwise.

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The summary below is from the full report titled “Usefulness of Ultrasonography in the Management of Nodular Thyroid Disease.” It is in the 7 November 2000 issue of Annals of Internal Medicine (volume 133, pages 696-700). The authors are E Marqusee, CB Benson, MC Frates, PM Doubilet, PR Larsen, ES Cibas, and SJ Mandel.