Doctor's Answers (3)
Thyroid nodules are solid or fluid-filled lumps that form within your thyroid gland. They are more commonly discovered as a person grows older.
90 to 95% of nodules found in the thyroid gland are non-cancerous. Only 5 to 10% of thyroid nodules are cancerous.
We usually look at the ultrasound characteristics of a nodule to determine if the nodule is suspicious to be cancerous. If there are any suspicious ultrasound features, a fine needle biopsy of the nodule will be recommended to further evaluate the nodule. There is unfortunately no blood test that can help to diagnose thyroid cancer.
A person with multiple thyroid nodules needs to be monitored at intervals for changes in the sizes and ultrasound characteristics of the nodules. Non-cancerous thyroid nodules can also increase in size with time. Although most nodules are non-cancerous, there is a very small risk of a non-cancerous nodule turning cancerous with time. The time interval of monitoring may be lengthened if there is no significant change in the nodules with time, but monitoring should not be stopped.
You should also see a doctor earlier if there is increase in the size of your thyroid gland (located at the lower part of the neck in the front) or if you encounter symptoms of breathing or swallowing difficulty.
Thyroid nodules are common growths on the thyroid gland. It is clinically palpable (can be felt on neck examination) in 5-10% of the population and detected on ultrasound in up to 30% of the population. Majority of thyroid nodules (>90%) are benign and can be monitored. They usually remain stable or may even grow in size but they very rarely become smaller.
One of the most widely used guidelines by doctors managing thyroid nodules is the American Thyroid Association (ATA) Guidelines. Based on these guidelines, the decision to follow up a thyroid nodule depends largely on the findings from the initial "needle test" (known as fine needle aspiration and cytology whereby a small needle and syringe is used to extract some cells from the thyroid nodule) and the ultrasound features of your thyroid nodules.
If your initial needle test showed that your thyroid nodules are benign and the ultrasound features of your thyroid nodules has no or low suspicious features, you can monitor these lesions. It is also important to note that any thyroid nodule larger than 4 cm will have a slightly higher risk of the FNAC being inaccurate and some surgeons do recommend surgical removals for such lesions.
As for the duration of the monitoring, unfortunately there has been no clear consensus, even from ATA guidelines. However, studies have shown that the chances of a thyroid cancer detected after 3 years of follow up of stable thyroid nodules with no suspicious features on ultrasound is extremely low (<1%). The frequency of follow up ultrasound has been recommended at 12-24 months. I do follow up most of my patients with benign stable thyroid nodules for at least 3 years.
You should also ensure that your thyroid hormones are checked on a regular basis to ensure that your thyroid glands are not over- or under producing these hormones.
Hope this helps and all the best!