A lymph node biopsy removes lymph node tissue to be looked at under a microscope for signs of infection or a disease, such as cancer. Other tests may also be used to check the lymph tissue sample, including a culture, genetic tests, or tests to study the body's immune system (immunological tests).

Lymph nodes are part of the immune system. They are found in the neck, behind the ears, in the armpits, and in the chest, belly, and groin. See an illustration of lymph nodes and the immune system.

Lymph nodes in healthy people are usually hard to feel. However, lymph nodes in the neck, armpit, or groin can get bigger and become tender. Swollen lymph nodes usually mean an infection, but the swelling can also be caused by a cut, scratch, insect bite, tattoo, a drug reaction, or cancer.

There are several ways to do a lymph node biopsy. The lymph node sample will be looked at under a microscope for problems.

• A fine-needle aspiration biopsy puts a thin needle into the lymph node and removes cells to look at. A needle biopsy is done to check the cause of a big lymph node.
• A core needle biopsy uses a needle fitted with a special tip. The needle goes through the skin to the lymph node to take a sample of tissue about the size of a pencil lead.
• An open biopsy makes a cut in the skin and removes the lymph node. If more than one lymph node is taken, the biopsy is called a lymph node dissection. Open biopsy and lymph node dissection let your doctor take a bigger sample than a needle biopsy.

Why It Is Done

Lymph node biopsy is done to:

• Check the cause of enlarged lymph nodes that do not return to normal size on their own.
• Check the cause of symptoms, such as an ongoing fever, night sweats, or weight loss.
• Check to see if a known cancer has spread to the lymph nodes. This is called staging and is done to plan cancer treatment.
• Remove cancer.

How To Prepare

Tell your doctor if you:

• Are taking any medicines.
• Are allergic to any medicines, including anesthetics.
• Are allergic to latex.
• Have any bleeding problems or take blood thinners, such as aspirin, heparin, warfarin (Coumadin), enoxaparin sodium (Lovenox), or clopidogrel bisulfate (Plavix).
• Are or might be pregnant.

You will be asked to sign a consent form. Talk to your doctor about any concerns you have regarding the need for the biopsy, its risks, how it will be done, or what the results will indicate. To help you understand the importance of the biopsy, fill out the medical test information form(What is a PDF document?).