What is a sentinel lymph node (SLN) biopsy?
Sentinel lymph node (SLN) biopsy is a procedure in which the sentinel lymph node is 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. A negative SLN biopsy result suggests that cancer has not spread to the lymph nodes. A positive result indicates that cancer is present in the SLN and may be present in other lymph nodes in the same area (regional lymph nodes). This information may help the doctor determine the stage of cancer (extent of the disease within the body) and develop an appropriate treatment plan. What happens during the SLN biopsy procedure? In SLN biopsy, one or a few lymph nodes (the sentinel node or nodes) are removed. To identify the sentinel lymph node(s), the surgeon injects a radioactive substance, blue dye, or both near the tumor. The surgeon then uses a sca
