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, it is done 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 lie on the examination table. You may be given medicine to calm you and make you sleepy.
- The biopsy site is cleansed.
- The health care provider injects a local anesthetic (numbing medicine) into the area. Sometimes, general anesthesia is used, which means you are asleep and pain-free.
- A small surgical cut (incision) is made. The lymph node or part of the node is removed.
- The incision is closed with stitches and a bandage is applied.
- An open biopsy may take 30 to 45 minutes.
For some cancers, a special way of finding the best lymph node to biopsy is used. This is called sentinel 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) node. This node is called the sentinel node. It is the first lymph node to which a cancer spreads.
- The sentinel node and possibly one or two other lymph nodes are removed.
Lymph node biopsies in the belly may be done with a laparoscope. This is a small tube with a light and camera that is inserted through a small incision in the abdomen. The lymph node is located and a piece of it is removed. This is usually performed under general anesthesia, which means the person having this procedure will be asleep and pain-free.
After the sample is removed, it is 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 the Test will Feel
When the local anesthetic is injected, you will feel a prick and a mild stinging. The biopsy site will be sore for a few days after the test.
After an open or laparoscopic biopsy, the pain is mild and you can easily control it with an over-the-counter pain medicine. You may also notice some bruising or fluid leaking for a few days. The incision should heal in 10 to 14 days. Follow instructions for taking care of the incision. While the incision is healing, avoid any type of intense exercise or heavy lifting.
How to Prepare for the Test
Tell your provider:
- If you are pregnant
- If you have any drug allergies
- If you have bleeding problems
- What medicines you are taking (including any supplements or herbal remedies)
Your provider may ask you to:
- Stop taking any blood thinners, such as aspirin, heparin, warfarin (Coumadin), or clopidogrel (Plavix) 5 to 10 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.
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 provider decide about further tests and treatments.
Lymph node biopsy may result in any of the following:
- 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)
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:
Why the Test is Performed
The test is used to diagnose cancer, sarcoidosis, or an infection (such as tuberculosis):
- When you or your provider feel swollen glands and they do not go away
- When lymph nodes are present on a CT or MRI scan
- For some people with breast cancer or melanoma, to see if the cancer has spread (sentinel lymph node biopsy)
The results of the biopsy help your provider decide on further tests and treatments.
Chernecky CC, Berger BJ. Biopsy, site-specific - specimen. In: Chernecky CC, Berger BJ, eds. Laboratory Tests and Diagnostic Procedures. 6th ed. Philadelphia, PA: Elsevier Saunders; 2013:199-202.
Young NA, Dulaimi E, Al-Saleem T. Lymph nodes. In: Bibbo M, Wilbur DC, eds. Comprehensive Cytopathology. 4th ed. Philadelphia, PA: Elsevier Saunders; 2015:chap 25.