Thyroid nodules and thyroid nodule biopsy


Endocrinology, Medicine, Thyroid Disease

Today, many more imaging procedures are being done and people are more commonly being diagnosed with thyroid nodules. Most of the time, the original test ordered was not meant to look at the thyroid at all, but it may have picked up a small abnormality on the thyroid gland due to how close the thyroid is to other important parts of the neck. We will use a fishing analogy to explain how we “fish” in thyroid nodules.

Lets take a fishing trip so that you understand more about thyroid nodules.


What is a thyroid nodule?

Thyroid nodules are like small lakes within the thyroid gland. Having nodules in the thyroid is very common and the odds increase as you age. At 50 years old, 1/2 of all people have thyroid nodule. As you get older, the nodules may fill with more fluid as they continue to grow slowly.

Because these “lakes” are within the thyroid itself, they cannot be seen with the naked eye. Similar to how fishermen use sound waves (ultrasound) to find the bottom of the water they are fishing in, doctors use an ultrasound machine to help visualize these thyroid nodules (or “lakes”. Using the ultrasound, a doctor can tell how deep and wide the thyroid nodules are, how rough or smooth the borders are, and if there is any material floating within the fluid inside the nodule. While ultrasound may work to look at the “lakes” within the thyroid, it does not tell you anything about the type of “fish swimming in thyroid lakes”.

Doctors use ultrasound to detect thyroid nodules

Thyroid Nodule Biopsy:

Most lakes are filled with healthy trout and other freshwater fish. In fact, 95% of thyroid nodules are filled with healthy cells . However, a rare thyroid “lake” might contain dangerous fish. A piranha filled “lake” can be bad for your health. Most of the time, you can’t tell just by looking at a lake if it’s safe or if there are piranhas lurking. A fisherman would use his fishing pole to catch some fish to see what is in the water.

To do a thyroid nodule biopsy, doctors use needles as their pole, and hope to catch cells instead of fish. This procedure is called fine needle aspiration biopsy. 5% of fishing trips in thyroid nodules discover dangerous, suspicious cells in them.

Thyroid biopsy results: 95% of thyroid nodules are filled with healthy normal cells.
Thyroid biopsy results: 5% of all thyroid nodules have abnormal cells within them.
95% of thyroid nodules have normal cells and 5% of thyroid nodules have abnormal cells.

Thyroid Nodule Size

Doctors do not go fishing in very small nodules. After all, you are not likely to catch a fish in a super tiny lake. Doctor’s typically recommend fishing for dangerous cells only if the lake is greater than, or equal to, 1 centimeter. If a thyroid nodule is larger (up to 4 centimeters), catching dangerous fish in that lake becomes more difficult. Sometimes the nasty piranhas can be tricky. Even though the fisherman tries to catch them, the piranhas can be hiding in a corner of the lake. In that situation, your doctor may recommend an operation to remove part, or all, of the thyroid.

Large thyroid nodules: Those that are bigger than 4 cm, can be difficult to biopsy because cells can hide within its borders.

Large thyroid nodules: Those that are bigger than 4 cm, can be difficult to biopsy because cells can hide within its borders. 
About the Authors

Chris Palmeiro D.O. M.Sc.


Dr. Palmeiro is Chairman of Endocrinology at the HealthAlliance of the Hudson Valley, he also serves patients with intellectual and developmental disabilities at the Westchester Institute of Human Development in Valhalla, New York. He has a Masters of Science degree in clinical nutrition and is a diplomate of the American Board of Internal Medicine. His interests within the realm of endocrinology include nutrition support, obesity counseling and the progressive management of diabetes.


Rishi Anand M.D.

Dr. Anand is a board certified Endocrinologist. He graduated magna cum laude from the accelerated 7 year Renssaelear Polytechnic Institute-Albany Medical College combined physician scientist program. He practices Endocrinology in Bristol, PA. There, he treats a wide range of Endocrine disorders including diabetes, thyroid disease, and other hormonal imbalances.

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Last Modified: Mar 4, 2018 @ 4:48 pm

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