 Patients 18 years of age and older with an aggressive non-Hodgkins lymphoma that has relapsed after treatment or is not responding to chemotherapy may be eligible for this study. Candidates will be screened with a medical history and physical examination. Other tests that may be required include blood and urine tests; lung function studies; imaging tests such as magnetic resonance imaging, computed tomography and x-rays; and biopsy surgical removal of a small tissue sample of tumor, bone marrow, or other tissue. 