Sentinel Lymph Node Biopsy

Lymph flow within the breast tissue is largely directed toward the axillary lymph nodes. Therefore, cancer cells that have acquired the ability to spread generally first migrate to the axillary lymph nodes. Knowing the status of the axillary lymph nodes in breast cancer patients is important for diagnosis, treatment, and follow-up.

Removal of the axillary lymph nodes is only effective for invasive tumors. In situ cancers (those confined to the milk ducts) theoretically do not require axillary slaughter, as they do not travel to the lymph nodes.

Technique: Blue dye (isosulfan blue or methylene blue), either alone or in combination with a radioactive substance, is injected into the tumor area or under the nipple. The dye reaches the first (sentinel) lymph node in the armpit within 5-7 minutes. The number of sentinel lymph nodes may be more than one; the average is two. These lymph nodes are removed and examined for tumor cells. If no tumor cells are seen, the procedure is terminated; there is no need to remove other lymph nodes in the armpit.