A sentinel node is the first lymph a tumor drains into. So, it's the first place that cancer is likely to spread. In breast cancer, the sentinel node is usually one of the axillary lymph nodes in the armpit. A sentinel node breast biopsy can be performed at the same time as a lumpectomy or a mastectomy. During the biopsy, one or more lymph nodes are removed. These are sent to the lab to be studied. If there are cancer cells in the sentinel node, this means the cancer has likely spread outside the breast. But if no cancer cells are found in the sentinel node, this means the cancer has probably not spread. A sentinel node biopsy gives the doctors valuable information, with less risk to you than some other procedures.
How Is the Sentinel Node Found?
There are two methods for finding the sentinel node. Your surgeon may do one or both of these techniques:
- A blue dye may be injected near the breast tissue. Then, its path into the lymph nodes is tracked. The dye collects in the sentinel node.
- A small amount of a safe radioactive solution may be injected near the tumor. A gamma detector is then used to find the "hotspot," which is the node where the solution has collected.
Understanding the Risks
Lymph node surgery involves certain risks. Your surgeon can discuss them with you. These include:
- Fluid collection (seroma)
- Pain or numbness
- Long-term swelling of the arm (lymphedema)