Sentinel node biopsy avoids the need to remove lymph nodes that are not cancerous. This procedure was developed to avoid the procedure with the armpit and to learn more about which lymph nodes should be removed.
An injection of a tracer is done the day before or the day of surgery to help the surgeon locate the first lymph nodes under the arm on the affected side called sentinel (guard) lymph nodes. The surgeon will remove between one and four lymph nodes. Only the nodes that pick up the tracer will be removed and tested. The nodes removed are then sent to the lab and are examined by the pathologist, who will determine if they contain cancer or if they are cancer free.
During axillary lymph node dissection, the surgeon will remove a group of lymph nodes in the armpit on the affected side to help determine what kind of therapy you will receive after your surgery. You will not know how many lymph nodes were removed until the pathology report comes back. The surgeon does not remove the lymph nodes one by one, but instead takes an area of tissue from under the arm. Some nodes may contain cancer and some may be cancer free. All will be examined and tested by the pathologist to determine the number of lymph nodes that contain cancer.
Whether you have a lumpectomy or a mastectomy, you and your surgeon may choose to remove some of the nodes in your armpit to:
Removal of lymph nodes may contribute to lymphedema, a swelling of the arm on the affected side caused by an abnormal build-up of fluid.
The risk of lymphedema is anywhere from five to 17 per cent for those having a sentinel lymph node biopsy, and about 20 to 53 per cent for those having an axillary lymph node dissection.