What does a hypoechoic thyroid nodule mean?
The thyroid is a small gland in the front part of the neck that produces hormones to regulate the body's metabolism. Nodules can develop on this gland due to the growth of thyroid tissue or a cyst.
In this article, we explore what hypoechoic nodules are and whether there is a risk of cancer. We also discuss causes and what happens after a doctor detects a hypoechoic nodule.
What is a hypoechoic nodule?
A doctor may find a hypoechoic thyroid nodule while checking a person's neck.
If a thyroid nodule is big enough, it can cause a lump or swelling in the neck that a person might be able to feel. A doctor may also discover thyroid nodules during a routine examination or an imagining test of a person's head and neck.
Doctors typically evaluate thyroid nodules using an ultrasound examination, or sonogram.
Thyroid nodules have specific characteristics that allow a doctor to assess the potential risk of thyroid cancer. For example, cystic or fluid-filled thyroid nodules are often benign, which means they are noncancerous.
The echogenicity refers to the brightness of a thyroid nodule relative to the rest of the thyroid tissue. Hypoechoic nodules are darker than the surrounding thyroid tissue, which suggests that the nodules are solid rather than fluid-filled.
Is there a cancer risk?
Most thyroid nodules are benign. According to the American Thyroid Association (ATA), about 5% of thyroid nodules develop into thyroid cancer.
The ATA also note that solid hypoechoic thyroid nodules have a higher chance of becoming cancerous compared to cystic or fluid-filled lesions. However, other characteristics, such as size, may also indicate the potential risk of a nodule developing into thyroid cancer. Doctors will recommend further testing if necessary.
If a doctor suspects that a nodule is cancerous, they may perform a fine-needle biopsy to take a small sample of cells for further analysis.
According to the ATA, around 50% of people have a detectable thyroid nodule by the age of 60 years. However, many people do not know that they have a thyroid nodule.
Doctors are not exactly sure what causes most thyroid nodules. However, certain conditions can increase the risk of developing thyroid nodules, including:
- Hashimoto's thyroiditis, which is an underlying autoimmune condition and the most common cause of hypothyroidism (underactive thyroid).
- Iodine deficiency, which can also lead to an enlarged thyroid gland, or goiter. However, iodine deficiency is very uncommon in developed countries, such as the United States.
What happens next?
If a doctor detects a hypoechoic thyroid nodule on an ultrasound examination, they may recommend that the person undergoes additional testing or surgery. We discuss these options below.
A doctor may order blood tests to check if the thyroid is functioning normally. Blood tests can measure the levels of thyroid stimulating hormone and thyroxine, which can indicate if a person has hypothyroidism or hyperthyroidism (overactive thyroid).
Nuclear thyroid scan
Less commonly, a doctor may recommend a nuclear thyroid scan. This test can help evaluate nodules that cause hyperthyroidism.
A fine needle biopsy is a quick procedure that doctors can often perform in their office or clinic. It involves inserting a fine needle through the skin of the person's neck and into the nodule to take a small sample of tissue. The doctor may use ultrasound scanning to help guide the needle.
A scientist will then examine the tissue sample under a microscope to check for the presence of cancerous cells.
A doctor may recommend surgery to remove potentially cancerous thyroid nodules.
If a doctor suspects that a thyroid nodule is cancerous, they will usually recommend a thyroidectomy, which is a surgical procedure to remove part or all of the thyroid gland. Following a total thyroidectomy, people need to take hormone replacement tablets for the rest of their lives to prevent symptoms of hypothyroidism.
If thyroid cancer is small and confined to the thyroid gland, then surgery may be enough to cure the cancer without further treatment. However, if the cancer spreads to the lymph nodes or other parts of the body, a person may require additional treatments.
Other treatment options can include:
Doctors may also recommend surgery for people with noncancerous thyroid nodules that are causing symptoms such as vocal changes and swallowing or breathing difficulties.
Thyroid nodules develop on the thyroid gland. These nodules are widespread, but most are benign.
Doctors typically evaluate thyroid nodules using ultrasound scans. Hypoechoic thyroid nodules appear dark relative to the surrounding tissue. These type of nodules are usually solid rather than a fluid-filled lesion.
If a doctor suspects that a thyroid nodule may be cancerous, they will recommend additional testing, such as blood tests and biopsies.
The main treatment for cancerous nodules is surgical removal of part or all of the thyroid gland. A doctor may also recommend the removal of noncancerous nodules that are causing problems.