Sentinel Lymph Node Biopsy

Sentinel Lymph Node (SLN) Biopsy is a diagnostic procedure used to determine whether breast cancer has spread (metastasized) to axillary lymph nodes (i.e., lymph glands under the arm). When breast cancer cells begin to escape from the primary tumor site in the breast, they travel to the lymph nodes under the arm; the first lymph node they reach is the '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.

A negative SLN biopsy result suggests that cancer has not spread to the lymph nodes.