Patients ages 12 and older who have LYG and who are not pregnant or breast feeding may be eligible for this study. Alpha interferon or chemotherapy, or both, will be used. Alpha interferon is a protein the body naturally produces. If patients have grade 3 disease, they will usually receive EPOCH-rituximab (EPOCH-R) chemotherapy (each letter representing a drug). If patients have grade 1 or 2 disease, the will usually receive alpha interferon. If patients have LYG after receiving alpha interferon and/or EPOCH-R, they may receive rituximab alone or with alpha interferon. Rituximab is an antibody, binding to a specific molecule (CD20) present on most B-cell lymphomas. Doses of several drugs in EPOCH-R may be increased if patients tolerated them in the previous cycle. If patients respond to EPOCH-R but still have low grade LYG, they may receive alpha interferon. Researchers will also try to obtain a biopsy of patients lesions, to help in understanding the disease.