TI-RADS Score Explained: What Your Report Actually Says

Q: At what size is a thyroid nodule biopsied?

For TI-RADS 4 and 5, generally above about 1.5 centimeters. Nodules under one centimeter are usually watched rather than biopsied even when they look suspicious. High risk history, such as radiation exposure or thyroid cancer in the family, can lower the threshold.

Someone hands you an ultrasound report, says see you in a year, and leaves the room. And you sit there thinking, what am I supposed to do with this?

I know how nerve wracking that is. So here is what the report, and the TI-RADS score on it, is telling you, in the order that actually matters.

Key takeaways

Size tells you whether a thyroid nodule is in your way. It does not necessarily tell you whether it is dangerous.
TI-RADS 2 is not a concern. TI-RADS 4 carries roughly a 35 percent chance of malignancy. TI-RADS 5 is around 80 percent.
For TI-RADS 4 and 5, a biopsy will be done if the nodule is larger than 1.5 and 1.0 cm, respectively, and nodules under one centimeter are watched even when they look suspicious.
A cyst, a sac of fluid, is not a malignancy concern, and a toxic nodule making excess thyroid hormone carries almost zero chance of cancer.
Radiation exposure or thyroid cancer in the family lowers the size at which I biopsy, which is why the history matters as much as the report.

Does the size of a thyroid nodule matter?

Yes, but not in the way most people fear. The size of a thyroid nodule tells you whether it is in your way. It does not tell you whether it is dangerous. A 4.6 centimeter nodule, which is what one person wrote in about, is very large. It is taking up space.

You can probably see it and feel it. It may be affecting your swallowing or your voice. If it is doing any of that, it matters regardless of whether it is benign, and a nodule like that can be removed or ablated to relieve the compression.

Does 4.6 centimeters automatically mean cancer? No. What matters is what the nodule is made of.

If this is the question you came in with, it is the one we answer in your first hour here. New patients are seen within two weeks and you do not need a referral. Call or text (817) 380-4880.

What is a thyroid nodule made of, and why does that matter more than size?

What a thyroid nodule is made of matters more than its size. If it is a cyst, a sac of fluid, we are not worried about malignancy. The only question is whether it is bothering you. If it is solid, then the thing that matters is the score on the report.

A lower score is a less risky looking nodule. A higher score carries a higher risk of thyroid cancer. We biopsy, intervene or remove according to that score and the size together, not according to size alone.

What does a TI-RADS score mean?

A TI-RADS score grades how suspicious a thyroid nodule looks on ultrasound, and the grade tells us at what size a biopsy is worth doing. TI-RADS is the scoring system from the American College of Radiology, and it is on almost every thyroid ultrasound report you will see. It works like the BI-RADS score on a mammogram.

There is also a system from the American Thyroid Association, but TI-RADS is what radiologists report.

TI-RADS 2 is not a concern. We do not worry about these.

TI-RADS 4 is moderately suspicious. Across everyone with a 4, roughly 30 percent, give or take, will have a malignancy in that nodule.

TI-RADS 5 is highly suspicious. The correlation with thyroid cancer is around 80 percent.

So if your report says a 1.7 centimeter nodule needs a biopsy, you are almost certainly looking at a 4 or a 5. Above about 1.5 centimeters with those scores, we want a piece of it, to find out what it is made of and whether anything else needs to happen.

Why would a nodule under one centimeter not be biopsied?

Because below one centimeter, even a high risk thyroid nodule is generally not biopsied. It is watched until it reaches a centimeter or more. One person who wrote in described a six by six millimeter nodule, hypoechoic, with a few specks of calcification.

Those specks are probably microcalcifications, also reported as punctate echogenic foci, and both hypoechoic texture and microcalcifications are features of higher risk nodules. But at six millimeters we are not biopsying it yet. We are following it.

The same person had hyperthyroidism, and asked whether that raised the risk. It does not, on its own. And if the nodule turns out to be a toxic nodule, one that is making thyroid hormone it should not be making, toxic nodules carry almost zero chance of malignancy.

Are multiple thyroid nodules a problem?

Multiple thyroid nodules are not a problem by number alone. The average person is likely to have a nodule. Some people make one, some make none, and some make so many that the gland looks like a bunch of grapes. Having many does not mean any one of them is bad, and it does not mean you lose your thyroid.

What matters is what each nodule is made of and, for the high risk ones, how big they are. That is what decides when, whether and what we do about biopsy or surgery.

My nodule is 2.6 centimeters and they said come back in a year. Is that right?

For a 2.6 centimeter thyroid nodule, a one year follow up may well be right. If the nodule is TI-RADS 2 or a cyst, an ultrasound in a year is perfectly reasonable, because the risk of thyroid cancer is minimal. Size without a suspicious score is not an emergency.

What I would want to know is the score, and I would want to know your history. Radiation exposure, family history of thyroid cancer and a few other factors change my threshold. In a high risk patient I biopsy at a smaller size than the chart says. That decision only gets made if someone takes the history, which is the reason to see an endocrinologist rather than only reading the report.

Where this leaves you

Size tells you whether the nodule is in your way. The TI-RADS score tells you whether we think it’s dangerous. A 2 is not a concern, a 4 is roughly 30 percent, a 5 is around 80, and under one centimeter we watch even the suspicious ones. Your history can move the biopsy threshold, and the report cannot see your history.

See your own numbers, not a guess. Bring the report. We read the score, take the history, and tell you plainly whether a biopsy is warranted, and if it is, we do it here. A new consultation is an hour, $400, and includes the first follow up. To book your consultation, call or text (817) 380-4880.

Frequently asked questions

What does a TI-RADS score mean on a thyroid ultrasound?

A TI-RADS score grades how suspicious a thyroid nodule looks. TI-RADS 2 is not a concern. TI-RADS 4 is moderately suspicious, with roughly a 30 percent chance of malignancy. TI-RADS 5 is highly suspicious, around 80 percent. The score, with the size, decides whether a biopsy is warranted.

At what size is a thyroid nodule biopsied?

For TI-RADS 4 and 5, generally above about 1.0 to 1.5 centimeters. Nodules under one centimeter are usually watched rather than biopsied even when they look suspicious. High risk history, such as radiation exposure or thyroid cancer in the family, can lower the threshold.

Does a large thyroid nodule mean cancer?

No. Size tells you whether the nodule is causing pressure, swallowing or voice symptoms. Cancer risk comes from what the nodule is made of and its TI-RADS score. A large nodule can be removed or ablated to relieve compression even when it is benign.

Are multiple thyroid nodules dangerous?

Not because there are many. Each nodule is judged on its own composition and score. Some people make one, some make none, and some make so many that the gland looks like a bunch of grapes. Having many does not mean any one of them is bad, and it does not mean you lose your thyroid.

Does hyperthyroidism increase thyroid nodule cancer risk?

No, hyperthyroidism on its own does not raise the cancer risk of a thyroid nodule. And if the nodule turns out to be a toxic nodule, one making thyroid hormone it should not be making, toxic nodules carry almost zero chance of malignancy.

Is a 4 centimeter thyroid nodule dangerous?

A 4 centimeter thyroid nodule is large enough to cause compression, which matters whether or not it is benign, and it can be removed or ablated for that reason. You can probably see it and feel it, and it may affect swallowing or voice. Whether it is cancerous depends on its composition (and TI-RADS score), not its size.

TI-RADS Score Explained: What Your Thyroid Nodule Report Actually Says