Staceyjo, that means removing lymph nodes from the neck. There are radical and modified dissections. I recently had 20 nodes removed in a modified version. There was a very minimum of pain and discomfort, and the swelling, while great at first, rapidly diminished. If your mother's doctors recommend this procedure, I would recommend that she agree and not be afraid. Keep checking back, because there are many people on this forum who are much more knowledgeable than I am, who will surely provide you with more than this very basic information. Good luck to you and your mom!
Joanna