Sentinel lymph node biopsy

A sentinel lymph node biopsy is a surgery to take out lymph node tissue to look for cancer that has spread into the lymph system. The sentinel lymph node is the first node in the body where cancer cells may be found if the cancer has spread from the original site.

A sentinel lymph node biopsy is done to:

• See if a known cancer, such as breast cancer or melanoma, has spread to the lymph nodes.
• Remove a few lymph nodes instead of removing all the lymph nodes in an area. If the sentinel lymph node does not have cancer, this biopsy takes less time, is simpler to do, and has a lower chance of long-term problems, such as ongoing swelling of an arm or leg (lymphedema).

• Your doctor injects a dye, a radioactive tracer, or both into your body near your cancer site. The dye stains the sentinel lymph node or nodes so they can be seen. The tracer travels to the sentinel lymph node where it can be detected.
• Your doctor removes the sentinel node or nodes. The node is looked at under a microscope for cancer cells. The results help your doctor decide whether to remove any more nodes.
• You will have some stitches and a bandage over the biopsy site.

• Follow the instructions exactly about when to stop eating and drinking. If you don't, your biopsy may be canceled. If your doctor told you to take your medicines on the day of the test, take them with only a sip of water.
• Understand exactly what surgery is planned, along with the risks, benefits, and other options.
• Tell your doctor ALL the medicines, vitamins, supplements, and herbal remedies you take. Some may increase the risk of problems during your test. Your doctor will tell you if you should stop taking any of them before the test and how soon to do it.
• If you take aspirin or some other blood thinner, ask your doctor if you should stop taking it before your surgery. Make sure that you understand exactly what your doctor wants you to do. These medicines increase the risk of bleeding.
• Make sure your doctor and the hospital have a copy of your advance directive. If you don’t have one, you may want to prepare one. It lets others know your health care wishes. It’s a good thing to have before any type of surgery or procedure.
• Be sure you have someone to take you home. Anesthesia and pain medicine will make it unsafe for you to drive or get home on your own.

Results are usually available within a few days.

The lymph node tissue is usually treated with special dyes (stains) that color the cells so problems can be clearly seen.

Normal

• The dye or tracer flows evenly to the sentinel lymph node.
• The lymph node has normal numbers of lymph node cells.
• The structure of the lymph node and the cells look normal.
• No cancer is present.

Abnormal

• The dye or tracer does not flow evenly to the sentinel lymph node.
• The sentinel lymph node cannot be identified.
• Cancer cells may be seen. Cancer cells may start in the lymph nodes, such as in Hodgkin lymphoma. Cancer cells may have spread, or metastasized, from other sites, such as in breast cancer or melanoma.

If the sentinel lymph node does not have cancer, no other nodes will need to be taken out.

If the sentinel lymph node contains cancer cells, more nodes may need to be removed.