Dear Barks: A sentinel lymph
nodeLymph node biopsy
Swollen glands
Swollen lymph nodes in the groin
Swollen lymph nodes under arm biopsy is a procedure that injects a dye and or radioactive substance into the area of the tumor. These substances will usually drain to the first lymph node(s). These are the sentinel lymph nodes. The theory is that if the cancer is going to spread to the lymph nodes, it will go to these nodes first. So if these first nodes are negative, then the rationale is that the nodes further down the chain should also be negative. There is a small incidence of "skip" metastasis where a sentinel node is negative and a node further down the chain is positive, so some surgeons like to remove a larger sample than just the sentinel node. Removing a sample of lymph nodes at the time of mastectomy is standard practice.
The reason to remove nodes is that it is an important part of the staging process and stage will help determine the treatment plan.