Hypoechoic nodes, or nodules, in the thyroid can be due to either malignant thyroid cancer or benign causes, such as thyroid cysts, adenomas or thyroiditis. Most thyroid cancers show as hypoechoic on ultrasound, says Radiopaedia. However, only about 5 percent of all thyroid nodules are malignant, explains American Academy of Family Physician. Larger hypoechoic nodules are more likely to be malignant.Continue Reading
Other features seen on ultrasound can indicate whether a hypoechoic thyroid nodule is potentially malignant. Nodules larger than one centimeter or taller than they are wide are considered suspicious for malignancy. Other indications of a cancerous nodule include microcalcifications or blood flow present within the nodule, reports Radiopaedia. Malignant nodules may also invade nearby structures.
Doctors use a type of biopsy called fine needle aspiration to determine whether a thyroid nodule found on ultrasound is benign or malignant; this test can take place in a doctor’s office or a hospital. The doctor often uses local anesthesia for the procedure. He uses a very thin needle to take a sample of cells and fluid from the thyroid. This procedure is simple and usually painless, although a patient may feel some pressure or have slight bruising afterwards, explains MedlinePlus. The cells are sent to a pathologist, who examines them to determine whether the cells come from a benign growth or a cancerous tumor.Learn more about Conditions & Diseases