This test involves taking a small tissue sample, called a biopsy, from one or more lymph nodes. The lymph nodes are small, oval-shaped glands found throughout the body, interconnected by lymph vessels. These form a circulatory system all their own called the lymphatic system.
The test is usually done when lymph nodes are enlarged, and cancer or infection is suspected. The test checks to see if abnormal white blood cells or cancer cells are present.
There are two ways in which the biopsy is taken: a needle biopsy or an open biopsy. A needle biopsy is taken in this way: The enlarged lymph node to be biopsied is identified. The skin over the area is scrubbed with antiseptic, and a local anesthetic is injected under the skin.
When the skin is numb, a biopsy needle is placed through the skin and into the lymph node. A small tissue sample is removed when the needle is withdrawn. Tissue can also be drawn up into the needle by suction; this is called fine needle aspiration (FNA).
An open biopsy involves removing all or part of a lymph node through surgery. The nature of the surgery and anesthetic depends upon the size and location of the tissue to be removed. After the biopsy sample is available, it is taken to the pathology laboratory for study.
Specific instructions are available from the healthcare professional.
Abnormal results may reveal different kinds of diseases, such as infection, noncancerous tumors or cancer.