My son had a rare form of cancer of called DFSP. He had surgery 2 yrs ago where they removed the tumer inlcuding all of his abdominal muscle, skin, a few ribs, and part of his sternim. They replaced his abdominal muscles with a synthetic mesh and skin, veins and muscle from his legs. They then kept him on gleevec for a year and then took him off. Last year during a check up they found a lymph node in his groin area and last month they found more lymph nodes right below his heart. The doctor said she was gonna watch them and that she wasn't worried. Should I be?