Lymph node biopsy

Definition

A lymph node biopsy is the removal of lymph node tissue for examination under a microscope.

The lymph nodes are small glands that make white blood cells (lymphocytes), which fight infection. Lymph nodes may trap the germs that are causing an infection. Cancer often spreads to lymph nodes.

How the Test is Performed

A lymph node biopsy is done in an operating room in a hospital, or at an outpatient surgical center. The biopsy may be done in different ways.

An open biopsy is surgery to remove all or part of the lymph node.

• You will lie on the examination table. You may be given a medicine to calm you and make you sleepy.
• The biopsy site will be cleansed, and the health care provider will inject a local anesthetic (numbing medication) into the area. (Sometimes, general anesthesia is used, which means you are asleep and pain-free.)
• A small surgical cut is made, and the lymph node or part of the node is removed. The area is closed with stitches and a bandage is applied.
• An open biopsy may take 30 - 45 minutes.

For some cancers, a special way of finding the best lymph node to biopsy is used. This is called sentinal lymph node biopsy, and it involves:

• A tiny amount of a tracer, either a radioactive tracer (radioisotope) or a blue dye, is injected at the tumor site.
• The tracer or dye flows into the nearest (local) sentinel node. This is the first lymph node to which any cancer would spread.
• The sentinal lymph node and possibly one or two other lymph nodes are removed.

The sample is then sent to the laboratory for examination.

A needle biopsy involves inserting a needle into a lymph node. This type of biopsy is done less often because the results are not as helpful as with an open biopsy.

How to Prepare for the Test

Tell your health care provider:

• If you are pregnant
• If you have any drug allergies
• If you have bleeding problems
• What medications you are taking (including any supplements or herbal remedies)

Your doctor may ask you to:

• Stop taking any blood thinners, such as aspirin, heparin, or warfarin 5 - 7 days before the procedure
• Not eat or drink anything after a certain period of time before the biopsy
• Arrive at a certain time for the procedure

You must sign a consent form.

How the Test Will Feel

When the local anesthetic is injected, you will feel a prick and a mild stinging sensation. The biopsy site will be sore for a few days after the test.

After an open biopsy, the pain is mild and you can easily control it with an over-the-counter pain medication. You may also notice some bruising or fluid leaking for a few days. The wound should heal in 10 - 14 days. During this time, avoid any type of intense exercise or heavy lifting.

Why the Test is Performed

The test is used to diagnose cancer, sarcoidosis, or an infection (such as tuberculosis):

• When you or your doctor feel swollen glands and they do not go away
• When lymph nodes are present on a CT or MRI scan
• For some patients with breast cancer or melanoma, to see if the cancer has spread (sentinel lymph node biopsy)

The results of the biopsy help your doctor decide on further tests and treatments.

Normal Results

If a lymph node biopsy does not show any signs of cancer, it is more likely that other lymph nodes nearby are also cancer-free. This information can help the health care provider decide about further tests and treatments.

What Abnormal Results Mean

Abnormal results may be due to many different conditions, from very mild infections to cancer.

For example, enlarged lymph nodes may be due to:

• Cancers (breast, lung, oral)
• HIV
• Hodgkin's lymphoma
• Infection (tuberculosis, cat scratch disease)
• Non-Hodgkin's lymphoma
• Sarcoidosis

Risks

• Bleeding
• Infection (in rare cases, the wound may get infected and you may need to take antibiotics)
• Nerve injury if the biopsy is done on a lymph node close to nerves (the numbness usually goes away in a few months)