Lymph node dissection

Lymph node dissection, also called lymphadenectomy, is the operation in which the lymph nodes are taken out of the area where a tumor is, so that a pathologist can look at them under the microscope and see whether there are malignant cells inside.

What makes the difference is how many. This is not opening a drawer and taking out one thing to look at it: it is emptying the drawer. In the radical version, it is not one or two that are removed: most or all of the nodes in that region are taken out. In the armpit, axillary dissection removes all the lymph tissue there, and that is no small matter, because 95 percent of the lymph from the breast drains through the axilla.

It is done mainly at four sites: the axilla in breast cancer, the groin, the neck and the retroperitoneum, which is the area behind the abdomen. Finding cancer cells in those nodes is associated with a higher risk of metastasis .. of the cancer traveling to other parts of the body .. and with a less favorable prognosis.

But emptying the axilla comes at a price. One common complication, and one that can end up being disabling, is arm lymphedema, the swelling from lymph that builds up when the channels it used to drain through have been removed: it shows up in about one in five people who have the surgery. That is why, once clinical trials showed that less invasive procedures worked, axillary dissection began to be done far less often.