Sentinel Lymph Node Biopsy

What is a sentinel lymph node (SLN)?

The sentinel lymph node is the first lymph node ("gland") to receive lymphatic drainage from a tumor. It is the sentinel, or "guard" of the rest of the lymph nodes. If the sentinel node is free of cancer cells, there is a >90% chance that the rest of the lymph nodes are also free of cancer.

What is SLN biopsy?

SLN biopsy is a procedure in which the sentinel lymph node is identified, removed and examined under a microscope to determine whether cancer cells are present. SLN biopsy is based on the idea that cancer cells spread (metastasize) in an orderly way from the primary tumor to the sentinel lymph node(s), then to other nearby lymph nodes.