Sentinel lymphatic mapping and biopsy is a procedure designed to target the axillary lymph nodes most likely to be involved with the primary lymphatic drainage from the breast .Sentinel node surgery is performed for staging of breast cancer to see if cancer cells have spread to the lymph nodes in the armpit, known as the axilla. Instead of removing all of the axillary lymph nodes which may be up to 30 in number, typically the 1 to 4 lymph nodes from the axilla which are most likely to have cancer cells are removed. This improves a pathologist ability to detect cancer in lymph nodes and also to decrease the chance of a complication from lymph node surgery. With sentinel lymph node biopsy, the possibility of nerve injury, arm swelling, and arm pain are diminished.