You will also receive Carmustine over one hour on the first day. From the second to the fifth day, you will receive cytarabine and etoposide twice a day. On the six day, you will receive melphalan once. Both drugs will be given through a catheter (plastic tube) that extends into the large chest vein. The catheter will be left in place throughout treatment on this study. Some participants, depending on their type of disease, will also receive rituximab. Rituximab will be given during the first day of chemotherapy then once a week for a total of 4 doses.