Known central nervous system (CNS) lymphoma Medically apparent central nervous system lymphoma or leptomeningeal disease Central nervous system lymphoma or leptomeningeal infiltration History of central nervous system lymphoma (either primary or metastatic). Central nervous system (CNS) lymphoma or leptomeningeal infiltration Known central nervous system lymphoma. Known central nervous system (CNS) lymphoma Current central nervous system (CNS) lymphoma or leptomeningeal infiltration. Known central nervous system (CNS) lymphoma Known central nervous system (CNS) lymphoma Known central nervous system lymphoma Known central nervous system (CNS) lymphoma Presence of central nervous system (CNS) lymphoma Patients with active known central nervous system (CNS) involvement of CLL or lymphoma; (patients with history of CNS CLL or lymphoma now in remission are eligible for the trial) Diagnosis of primary central nervous system lymphoma Prior therapy for central nervous system (CNS) lymphoma\r\n* Steroids not an exclusion Known central nervous system (CNS) lymphoma or leukemia Known central nervous system (CNS) lymphoma History of central nervous system lymphoma (either primary or metastatic). Central nervous system lymphoma, including lymphomatous meningitis Patients with active and/or untreated central nervous system (CNS) lymphoma will not be eligible History of central nervous system lymphoma (either primary or metastatic). Primary central nervous system (CNS) lymphoma Has known active central nervous system (CNS) lymphoma Has known active central nervous system (CNS) lymphoma Known central nervous system (CNS) lymphoma Central nervous system (CNS) or meningeal involvement, or cord compression by the lymphoma; history of CNS lymphoma Known central nervous system lymphoma Central nervous system (CNS) lymphoma Known active central nervous system lymphoma Active central nervous system lymphoma All patients with central nervous system lymphoma Central nervous system (CNS) lymphoma: CNS involvement by lymphoma, including parenchymal brain or spinal cord lymphoma or known presence of leptomeningeal disease prior to registration Patients with evidence of active central nervous system lymphoma Known central nervous system lymphoma Known central nervous system (CNS) lymphoma Active central nervous system (CNS) disease defined as symptomatic meningeal lymphoma or known CNS parenchymal lymphoma; a lumbar puncture demonstrating DLBCL at the time of registration to this study is not exclusion for study enrollment Active central nervous system lymphoma Known active central nervous system or leptomeningeal lymphoma Known history of, or clinically apparent, central nervous system (CNS) lymphoma or leptomeningeal lymphoma. Primary central nervous system (CNS) lymphoma Known central nervous system (CNS) lymphoma or leukemia Patients should not have evidence of active central nervous system lymphoma All patients with central nervous system lymphoma. Lymphoma involving the central nervous system Central nervous system (CNS) involvement by lymphoma including parenchymal brain or spinal cord lymphoma or known presence of leptomeningeal disease prior to registration Lymphoma involving the central nervous system Known active central nervous system or leptomeningeal lymphoma Current or past history of central nervous system lymphoma Patients with primary central nervous system (CNS) lymphoma Central nervous system lymphoma or leptomeningeal infiltration Known central nervous system lymphoma Known active central nervous system lymphoma or leptomeningeal disease Central nervous system lymphoma or leptomeningeal infiltration Participants with central nervous system (CNS) lymphoma Lymphoma involving the central nervous system Known central nervous system lymphoma (either primary or metastatic). Patients with active central nervous system (CNS) disease defined as symptomatic meningeal lymphoma or known CNS parenchymal lymphoma Known central nervous system (CNS) lymphoma Known central nervous system lymphoma or leptomeningeal disease, except subjects with a history of central nervous system lymphoma treated and in remission > 6 months Known central nervous system (CNS) lymphoma All patients with central nervous system lymphoma Known central nervous system lymphoma Known central nervous system (CNS) lymphoma Known central nervous system lymphoma Known central nervous system or primary mediastinal lymphoma All patients with history of central nervous system lymphoma Known active Central Nervous System (CNS) lymphoma. No active central nervous system (CNS) disease defined as symptomatic meningeal lymphoma or known CNS parenchymal lymphoma; a lumbar puncture demonstrating mantle cell lymphoma at the time of registration to this study is not an exclusion for study enrollment Primary central nervous system (CNS) lymphoma History of central nervous system lymphoma (either primary or metastatic) or leptomeningeal disease. Medically apparent central nervous system lymphoma or leptomeningeal disease Central nervous system lymphoma or leptomeningeal disease Active central nervous system (CNS) lymphoma Known central nervous system lymphoma History of lymphoma involving the central nervous system Known central nervous system (CNS) lymphoma Central nervous system (CNS) lymphoma All patients with active central nervous system lymphoma Clinical evidence of extra-central nervous system (CNS) (systemic) non-Hodgkin lymphoma Central Nervous System (CNS) Lymphoma or chronic immunosuppression-associated central nervous system (CNS) lymphoma. Medically apparent central nervous system lymphoma or leptomeningeal disease Primary central nervous system (CNS) lymphoma Central nervous system or leptomeningeal lymphoma Primary central nervous system (CNS) lymphoma Evidence of central nervous system lymphoma or lymphomatous meningitis Patients with active central nervous system (CNS) lymphoma Central nervous system (CNS) metastases from lymphoma or small cell lung cancer Known central nervous system (CNS) lymphoma, leptomeningeal lymphoma Known central nervous system lymphoma Central nervous system (CNS) lymphoma; active brain or leptomeningeal metastases. Diagnosis of primary central nervous system (CNS) lymphoma Known central nervous system (CNS) lymphoma Known central nervous system (CNS) lymphoma Patients with central nervous system (CNS) lymphoma are not eligible for the trial unless the disease had been treated and the subject remains without symptoms with no active CNS lymphoma. Have known central nervous system metastasis or Central Nervous System lymphoma; History or current evidence of central nervous system lymphoma History of primary central nervous system lymphoma or neoplastic central nervous system disease Known central nervous system (CNS) lymphoma or leukemia