Test Overview
A thyroid
biopsy is a procedure in which a small sample of
tissue is removed from the
thyroid gland and looked at under a microscope for
cancer, infection, or other thyroid problems. The
thyroid gland is found in front of the windpipe (trachea), just below the voice
box (larynx).
A sample of thyroid tissue can be taken by:
- Fine-needle biopsy. Your doctor puts a thin
needle through the skin and into the thyroid gland. Many thyroid specialists
like to use a needle biopsy method rather than surgery.
- Open
biopsy. Your doctor makes a cut (incision) through the skin to see the thyroid
gland. This method is done when other tests have not found the cause of your
symptoms.
- Core needle biopsy. Your doctor inserts a needle with a special tip and removes a sample of tissue about the size of a grain of rice.
Why It Is Done
A thyroid biopsy is done to:
- Find the cause of a lump (nodule) found in the
thyroid gland. Lumps in the thyroid gland may be found during a physical
exam or seen on a thyroid
ultrasound test or radioactive thyroid
scan.
- Find the cause of a
goiter. Symptoms of a goiter include breathing and
swallowing problems, a feeling of fullness in the neck,
and weight loss.
How To Prepare
Tell your doctor if you:
- Take any medicines regularly. Be sure your
doctor knows the names and doses of all your medicines.
- Are allergic to any medicines, including
anesthetics.
- Take a blood thinner, or if you have had bleeding problems.
Before having a thyroid biopsy, you may need to have blood
tests to see whether you have any bleeding problems or blood-clotting
disorders.
To prepare for a thyroid biopsy:
- You do not need to do anything before a needle
biopsy. You will be
awake during the biopsy.
- You will get
general anesthesia and be asleep during an open biopsy. Follow the instructions exactly about when to stop eating and drinking. If you don't, your procedure
may be canceled. If your doctor told you to take your medicines on the day of the procedure, take
them with only a sip of water.
Just before the test, you will remove your dentures (if you
wear them) and all jewelry or metal objects from around your neck and upper
body.
You will be asked to sign a consent form that says you understand the risks of the test and agree to have it done.
Talk to your doctor about any concerns you have regarding the
need for the test, its risks, how it will be done, or what the results will
mean. To help you understand the importance of this test, fill out the
medical test information form(What is a PDF document?).
How It Is Done
Needle biopsy
A needle biopsy is done in a
hospital, clinic, or your doctor's office. During the test, you will lie on
your back with a pillow under your shoulders, your head tipped backward, and
your neck extended. This position pushes the thyroid gland forward, making it
easier to do the biopsy. Do not cough, talk, or swallow when the needle is in place. A needle biopsy takes
about 5 to 10 minutes.
Before the biopsy, you may be given a
medicine (sedative) to help you relax. Your doctor will clean the
skin over your thyroid gland with a special soap.
Your doctor may
use an
ultrasound to guide the placement of the needle. He or
she will put a thin needle into your thyroid gland and take out a small amount
of thyroid tissue and fluid. The tissue is looked at under a microscope.
A small bandage is placed over the area where the needle was
inserted.
Open biopsy
An open biopsy of the thyroid gland is
done in an operating room by a
surgeon. It is done when other tests have not found
the cause of your symptoms. An open biopsy takes about an hour.
You
may be given a sedative to help you relax. An
intravenous (IV) line is inserted in a vein in your
arm for medicine and fluids. You will be asleep for the biopsy.
The
skin over your thyroid gland is cleaned with a special soap. A small cut
(incision) is made in your neck. A sample of thyroid tissue is taken or your
doctor can take out a lump if one is present. Some thyroid tissue may be sent
to the laboratory during the biopsy to see whether it has cancer cells. If
cancer cells are present, your doctor may take out more or all of the thyroid
gland.
The incision is closed with stitches. A bandage is put over
the stitches. Keep the biopsy site covered and dry for 48 hours. A small amount
of bleeding from the biopsy site can be expected. Ask your doctor how much
drainage to expect. Some people may need to stay in the hospital for one
night.
Open biopsy is not as commonly done as needle biopsy.
How It Feels
Needle biopsy
You may find it uncomfortable to
lie still with your head tipped backward.
During a needle biopsy,
you may feel a quick sting or pinch in your neck.
The biopsy site
may be sore and tender for 1 to 2 days. You can take nonprescription pain
medicine, such as acetaminophen, for the discomfort. Be safe with medicines. Read and follow all instructions on the label.
Open biopsy
You will be asleep and feel nothing
during the biopsy. After the biopsy, you may have some nausea and general muscle
aches and may feel tired for 1 to 2 days. You also may have a sore throat and
sound hoarse. Suck on throat lozenges or gargle with warm salt water to help
your sore throat.
The biopsy site may be sore and tender for 3 to
4 days. Your doctor will give you pain medicine for this.
After a thyroid biopsy, you may be more comfortable if
you keep your head up on a pillow when you lie down. Support the back of your
head and neck with both hands when you sit up to prevent discomfort at the
biopsy site.
Risks
There is a small chance of problems from a
thyroid biopsy, such as infection and bleeding.
After the test
Call your doctor immediately if
you have:
- A lot of bleeding through the
bandage.
- A hard time swallowing.
- Signs of infection,
such as:
- Increased pain, swelling, redness, or
warmth around the biopsy site.
- Red streaks spreading from the
biopsy site.
- Drainage of pus from the biopsy site.
- Swollen lymph nodes in the neck.
- Fever.
Results
A thyroid
biopsy is a procedure in which a small sample of
tissue is removed from the
thyroid gland and looked at under a microscope for
cancer, infection, or other thyroid problems. Results from a thyroid biopsy are
usually available in a few days.
Thyroid biopsy| Normal: | The biopsy shows normal thyroid
tissue. |
|---|
| Abnormal: | The biopsy sample shows thyroid disease
(such as inflammation of the thyroid gland), thyroid cancer, or a noncancerous
(benign) tumor. |
|---|
A thyroid
cyst is found at the time of a biopsy. Most cysts of
the thyroid gland are not cancerous. |
What Affects the Test
If you can't lie still during a needle biopsy, you may need to have general anesthesia.
What To Think About
- A normal (negative) report on a thyroid biopsy
does not mean for sure that the thyroid gland is healthy. It is possible that a
problem may have been missed. Many thyroid tumors are small, and the biopsy
sample may come from an area of the thyroid that is free from disease. A
fine-needle biopsy can have a
false-negative result.
- Your doctor may
not be able to use a needle biopsy to find out what is causing your symptoms.
An open thyroid biopsy may be needed.
- If a
thyroid nodule is found and thyroid hormone levels are
normal, most doctors recommend a thyroid needle biopsy instead of a radioactive thyroid scan.
- If a
thyroid nodule is found and high thyroid levels are present, a radioactive iodine
uptake (RAIU) test and a thyroid scan are generally recommended before a thyroid biopsy. Nodules
that cause hyperthyroidism are generally noncancerous (benign) and can be
treated with medicine or radioactive iodine. To learn more, see the
topic
Radioactive Iodine Uptake Test.
References
Other Works Consulted
- Chernecky CC, Berger BJ (2013). Laboratory Tests and Diagnostic Procedures, 6th ed. St. Louis: Saunders.
Credits
ByHealthwise Staff
Primary Medical ReviewerE. Gregory Thompson, MD - Internal Medicine
Kathleen Romito, MD - Family Medicine
Specialist Medical ReviewerAlan C. Dalkin, MD - Endocrinology