RATIONALE: Drugs used in chemotherapy use different ways to stop cancer cells from dividing so they stop growing or die. Monoclonal antibodies such as rituximab can locate cancer cells and either kill them or deliver cancer-killing substances to them without harming normal cells. Combining chemotherapy with monoclonal antibody therapy, total-body irradiation, and peripheral stem cell transplant may allow the doctor to give higher doses of chemotherapy drugs and kill more cancer cells.