I have had an ultrasound that showed hypoechoic nodules in my thyroid. Can you give me more information on what hypoechoic nodules are?
Thyroid nodules are very common — it is estimated that 20 to 40 percent of the population has them. They are nearly always benign (not cancerous). The goal of the physician, once a thyroid nodule has been detected, is to determine whether the nodule should be further evaluated to rule out cancer. A sonogram (ultrasound) of the thyroid gland is one of the best tests to evaluate thyroid nodules. When radiologists read the sonogram to look at specific features of the nodules, hypoechoic and hyperechoic are terms they use to describe what sort of echo "shadow" the nodule casts. Hypoechoic nodules cast off fewer or weaker echoes than the surrounding normal tissue, while hyperechoic nodules cast more or stronger echoes than the surrounding normal tissue.
Typically, benign thyroid nodules appear hyperechoic on the sonogram, while malignant (cancerous) thyroid nodules are more likely to be hypoechoic, casting off fewer or weaker echoes. However, the chance of any hypoechoic nodule being cancerous is still very low, because benign thyroid nodules are much more common. If a thyroid nodule requires further evaluation, the next step is generally to perform a fine needle aspiration (FNA) of the suspicious nodule, a test in which a thin needle is inserted into the nodule to extract cells for evaluation. Looking at these cells under a microscope helps to determine whether or not the nodule contains cancer cells.
Bottom line: You should speak with your doctor about your thyroid ultrasound results and ask whether the findings require further evaluation by a test such as an FNA.
Learn more in the Everyday Health Thyroid Cancer Center.