When you get a thyroid biopsy, your doctor will take a little bit of your thyroid or lumps (known as nodules) growing on it to test in a lab.
Nodules are very common in the thyroid, which is a butterfly-shaped gland in your neck. Although they can cause different problems, they’re usually not cancer.
Some conditions can make your thyroid grow in size. Doctors call this a “goiter.” You may need treatment for it, but more often than not, it’s not cancer either.
Before you get a thyroid biopsy, you’ll probably get blood tests to see how your thyroid is working and imaging tests, too. If they raise any concerns, your doctor will recommend a biopsy.
What Will a Biopsy Tell Me?
Sometimes, a nodule or goiter just sits there and isn’t dangerous.
When they do cause problems, it could be something like:
Cysts, fluid-filled nodules that can give you neck pain or make it hard to swallow. They’re very rarely cancer but still might need treatment.
Graves’ disease, which causes your thyroid to grow and make too many hormones.
Hashimoto’s disease, where your thyroid is damaged by your immune system, so it makes fewer hormones than normal and then swells.
Infection, where a virus causes pain and swelling in your thyroid.
Large nodules or goiters that are an issue because of their size. They can push into surrounding body parts and make it harder to breathe or swallow.
Toxic nodules or goiters, which are almost never cancer, can cause your thyroid to pump out too many hormones.
Cancer, which makes up about 10% of cases.
When Would I Need a Biopsy?
A biopsy helps your doctor find the cause of a nodule or goiter. But you don’t need it for all thyroid problems. For example, your symptoms, blood tests, and imaging will be enough to tell if you have Graves’ disease.
Your doctor will likely want to check on any nodule bigger than about 1 centimeter (about half an inch), especially if imaging shows that the nodule is solid, has calcium on it, and doesn’t have clear borders around it.
You might also get a biopsy without a nodule if you’re in a lot of pain and your thyroid is growing quickly.
Thyroid Biopsy Types
You’ll almost always get fine needle aspiration biopsy, but there may be reasons to get other ones, as well.
Fine needle aspiration (FNA) biopsy. This test uses a small needle. You’ll be awake, and the most you’ll feel is a small pinch. So you probably won’t need any numbing medicines.
With the help of ultrasound imaging, your doctor places the needle into your neck to pull out a sample for testing. You may feel the needle move around a little. And your doctor might repeat it a few times to get at different parts of the nodule or goiter.
Your doctor might take samples from lymph nodes near your thyroid as well.
The procedure takes about half an hour. You may get a small bandage where the needle went in. Then, you can go on with the rest of your day.
Core needle biopsy. This is like FNA, but with a bigger needle. If your doctor doesn’t get clear answers from an FNA biopsy, this one might be a good backup plan. Researchers are still looking at when and how to best use it.
Surgical biopsy. Doctors rarely use this method on the thyroid. It requires making an opening in your neck to remove the node. It may even mean removing half your thyroid. Because it’s surgery, you’ll get medicines to put you under during the operation. It also means a longer recovery.
What Happens Next?
You can get your results in as fast as a few days, though it could take up to 2 weeks. Ask your doctor when you should find out.
What happens next depends on what the biopsy showed. If it’s not cancer and you don’t have other symptoms, you and your doctor may do “watchful waiting.” That means follow-up visits on a schedule to check on things, like a change to a nodule or a new one showing up.
If it’s cancer, you’ll likely need surgery. Most thyroid cancers can be treated.
In other cases, you may need treatment for an underactive or overactive thyroid. Or for large nodules that get in the way of breathing or swallowing.
Sometimes, an FNA doesn’t give a sure answer. Often, the first step is to repeat it. If the results still aren’t clear, you and your doctor will talk about your options based on your symptoms and other test results. It could mean that you get another type of biopsy, thyroid surgery, or watchful waiting.
