The procedure of exploration and removal of the lymph nodes from the armpit for studying under the microscope is known as axillary lymph node dissection. This is undertaken to determine if the breast cancer has spread to your lymph nodes. There are two options for doing axillary lymph node dissection. The first option is to do a complete exploration in the armpit area for lymph nodes and removing as many as possible. The second option is to do a sentinel node biopsy. This procedure involves injection of a blue dye and some form of radioactive material into the tumor. The surgeon will then determine the pattern of lymphatic flow from the tumor by following the course of the blue dye and the radioactive material. This would lead to identification of the first lymph node into which a tumor drains, and the one that may most likely to contain cancer cells if a lymphatic spread has occurred. This is called the sentinel lymph node, and the surgeon will remove this lymph node to study under the microscope.
If this lymph node is involved with breast cancer, surgeon will do a full exploration of the armpit area nd will remove as many possible lymph nodes. This lymph node exploration surgery may be undertaken at the time of sentinel node biopsy or may be delayed for several weeks after the biopsy. If the sentinel node is not involved with cancer lymph node exploration is not done thus avoiding various complications associated with the lymph node dissection. Not every surgeon can perform the sentinel lymph node biopsy. This is a relatively new procedure and requires substantial expertise on the part of the surgical team. It may take some time for the surgeon to learn and to become an expert in sentinel lymph node biopsy. Also sentinel lymph node biopsy may not be the best option for every woman, Sentinel lymph node biopsy is done only if the tumor size is less than two inches. Obliviously if the doctor can feel enlarged lymph nodes in the armpit area, sentinel lymph node biopsy is not an appropriate choice.