A sentinel lymph node is defined as the first lymph node to which cancer cells are most likely to spread from a primary tumor. Sometimes, there can be more than one sentinel lymph node. A sentinel lymph node biopsy is a procedure in which the sentinel lymph node is identified, removed, and examined to determine whether cancer cells are present. A negative result implies that cancer has not yet spread to nearby lymph nodes or other organs. A positive result indicates that cancer is present in the sentinel lymph node and that it may have spread to other nearby lymph nodes and, possibly, other organs.

It is used in people who have already been diagnosed with breast cancer. It helps in staging of the breast cancer.

What to expect before the procedure? First, the sentinel lymph node (or nodes) must be located. To do so, a surgeon injects a radioactive substance, a blue dye, or both near the tumor. The surgeon then uses a device to detect lymph nodes that contain the radioactive substance or looks for lymph nodes that are stained with the blue dye.

Once the sentinel lymph node is located, Dr. Naresh will make a small incision in the overlying skin and removes the node. A pathologist then checks the sentinel node for the presence of cancer cells. If cancer is found, Dr. Naresh may remove additional lymph nodes, either during the same biopsy procedure or during a follow-up surgical procedure. It is usually done at the same time the primary tumor is removed. In some cases, the procedure can also be done before or even after (depending on how much the lymphatic vessels have been disrupted) removal of the tumor.

Sentinel lymph node biopsy may be done on an outpatient basis or may require a short stay in the hospital. The patient may experience lymphedema (swelling of lymph nodes) if more lymph nodes are removed. The patient might feel numbness, tingling, swelling, bruising, or pain at the site of the surgery, for which Dr. Naresh will prescribe medications and some exercises.