http://www.searchbreast.com/templates/Default/img/logo.gifhttp://www.searchbreast.com/http://www.searchbreast.com/lymph-nodes/http://www.searchbreast.com/lymph-nodes/Sentinel-Lymph-Node-Biopsy-Cancer-information-on-MedicineNet-com-l80.htmlThe sentinel lymph node is the first lymph node ("gland") to receive lymphatic drainage from a tumor. It stands sentinel over the tumor, so to speak.