What is a lymph node biopsy?

A lymph node biopsy is a test that checks for disease in your lymph nodes. Lymph nodes are small, oval-shaped organs located in different parts of your body. They’re found close to internal organs such as your stomach, intestines, and lungs, and are most commonly noted in the armpits, the groin, and the neck.

Lymph nodes are part of your immune system, and they help your body recognize and fight off infections. A lymph node may swell in response to an infection somewhere in your body. Swollen lymph nodes can appear as a lump beneath your skin.

Your doctor may find swollen or enlarged lymph nodes during a routine examination. Swollen lymph nodes that result from minor infections or insect bites typically don’t require medical care. However, to rule out other problems, your doctor may monitor and check your swollen lymph nodes.

If your lymph nodes remain swollen or grow even larger, your doctor may order a lymph node biopsy. This test will help your doctor look for signs of a chronic infection, an immune disorder, or cancer.

A lymph node biopsy can take place at a hospital, in your doctor’s office, or in other medical facilities. It’s typically an outpatient procedure, which means you don’t have to stay overnight at the facility.

With a lymph node biopsy, your doctor may remove the entire lymph node, or take a tissue sample from the swollen lymph node. Once the doctor removes the node or sample, they send it to a pathologist in a lab, who examines the lymph node or tissue sample under a microscope.

There are three ways to perform a lymph node biopsy.

Needle biopsy

A needle biopsy removes a small sample of cells from your lymph node.

This procedure takes about 10 to 15 minutes. While you’re lying on an examination table, your doctor will clean the biopsy site and apply medication to numb the area. Your doctor will insert a fine needle into your lymph node and remove a sample of cells. They’ll then remove the needle and put a bandage on the site.

Open biopsy

An open biopsy removes either a portion of your lymph node or the entire lymph node.

Your doctor can perform this procedure with local anesthesia, using a numbing medication applied to the biopsy site. You can also request general anesthesia that will make you sleep through the procedure.

The entire procedure takes between 30 and 45 minutes. Your doctor will:

  • make a small cut
  • remove the lymph node or portion of the lymph node
  • stitch the biopsy site closed
  • apply a bandage

Pain is generally mild after an open biopsy, and your doctor may suggest over-the-counter pain medications. It takes about 10 to 14 days for the incision to heal. You should avoid strenuous activity and exercise while your incision heals.

Sentinel biopsy

If you have cancer, your doctor may perform a sentinel biopsy to determine where your cancer is likely to spread.

With this procedure, your doctor will inject a blue dye, which is also called a tracer, into your body near the cancer site. The dye travels to the sentinel nodes, which are the first few lymph nodes into which a tumor drains.

Your doctor will then remove this lymph node and send it to a lab to check it for cancer cells. Your doctor will make treatment recommendations based on the lab results.

There are risks involved with any type of surgical procedure. Most of the risks of the three types of lymph node biopsy are similar. Notable risks include:

  • tenderness around the biopsy site
  • infection
  • bleeding
  • numbness caused by accidental nerve damage

Infection is relatively rare and can be treated with antibiotics. Numbness can occur if the biopsy is done near nerves. Any numbness typically disappears within a couple of months.

If you have your entire lymph node removed — this is called a lymphadenectomy — you could have other side effects. One possible effect is a condition called lymphedema. This can cause swelling in the affected area. Your doctor can tell you more.

Before scheduling your lymph node biopsy, tell your doctor about any medications that you’re taking. This includes non-prescription medications, such as aspirin, other blood thinners, and supplements. Also tell your doctor if you’re pregnant, and tell them about any medication allergies, latex allergies, or bleeding disorders you have.

Stop taking prescription and non-prescription blood thinners at least five days before your scheduled procedure. Also, don’t eat or drink for several hours before your scheduled biopsy. Your doctor will give you more specific instructions on how to prepare.

Pain and tenderness can last for a few days after a biopsy. Once you get home, keep the biopsy site clean and dry at all times. Your doctor may ask you to avoid showers or baths for a couple of days after the surgery.

You should also pay close attention to the biopsy site and your physical condition after the procedure. Call your doctor if you show signs of an infection or complications, including:

  • fever
  • chills
  • swelling
  • intense pain
  • bleeding or discharge from the biopsy site

On average, test results are ready within 5 to 7 days. Your doctor may call you with the results, or you may need to schedule a follow-up office visit.

Possible results

With a lymph node biopsy, you doctor is likely looking for signs of an infection, an immune disorder, or cancer. Your biopsy results could show that you have none of these conditions, or it could indicate that you may have one of them.

If cancer cells are detected in the biopsy, it could be a sign of one of the following conditions:

If the biopsy rules out cancer, your doctor may order additional tests to determine the cause of your enlarged lymph nodes.

Abnormal results of a lymph node biopsy could also mean you have an infection or immune system disorder, such as:

A lymph node biopsy is a relatively minor procedure that can help your doctor determine the cause of your swollen lymph nodes. Talk with your doctor if you have questions about what to expect with your lymph node biopsy, or the results of the biopsy. Also ask for information about any further medical tests your doctor may suggest.