Jefferson Health

Sentinel Lymph Node Biopsy

Whether you have breast-conserving surgery or a mastectomy, you may also have a procedure to remove some of the lymph nodes from under your armpit to examine if the cancer has spread. Lymph nodes are tiny bean-shaped organs into which various types of materials (bacteria, cancer cells) drain.

An important development in the staging of breast cancer is the increased use of the procedure called sentinel lymph node biopsy, as an alternative to full axillary lymph node dissection.

What Does Sentinel Lymph Node Biopsy Involve?

Sentinel node dissection, performed by breast surgeons of the Jefferson Breast Care Center, involves injecting a radioactive isotope and/or blue dye into the breast before surgery. As lymphatic fluid drains away from the breast, it first passes through certain lymph nodes located in key parts of the drainage system. These are called sentinel lymph nodes, because they seem to act as the gatekeepers. If the sentinel node is free of cancer, the odds are that there will be no cancer in the other nodes located downstream.