OBJECTIVES: I. Determine the radioimmunodetection performance of the imaging agent technetium Tc 99m LL2 monoclonal antibody (LymphoScan) in patients with low, intermediate, and high grade B-cell non-Hodgkin's lymphoma. II. Define the safety of an initial administration of technetium Tc 99m LL2 monoclonal antibody in these patients. III. Demonstrate that diagnostic imaging with this agent can correctly stage patients who have been diagnosed with this disease similarly to noninvasive conventional diagnostic modalities (CDMs), primarily CT scan and bone scan. IV. Demonstrate that imaging with technetium Tc 99m LL2 monoclonal antibody is at least as sensitive for detecting disease in various body sites as any other standard diagnostic imaging method. V. Compare patient management plans based on CDMs alone, technetium Tc 99m LL2 monoclonal antibody alone, and both CDMs and technetium Tc 99m LL2 monoclonal antibody. VI. Describe the human antimouse antibody production in these patients.