An axillary dissection is done to find out if the breast cancer has spread to lymph nodes under the arm. During an axillary dissection, some nodes are removed and examined under a microscope. Knowing whether there are cancer cells in the lymph nodes can help guide other treatment decisions.
A possible side effect of removing these lymph nodes is swelling of the arm, called lymphedema. It happens to about 10 percent to 30 percent of women who have had these nodes removed. Women who have swelling, tightness or pain in the arm after lymph node surgery should be sure to tell their doctor right away. Often there are measures to prevent or reduce the effects of the swelling.