PRIOR CONCURRENT THERAPY: Biologic therapy: No prior imaging studies with murine monoclonal antibodies showing reactivity with yttrium Y 90 monoclonal antibody MN-14 (90Y hMN-14) Chemotherapy: At least 4 weeks since prior chemotherapy and recovered Endocrine therapy: Not specified Radiotherapy: At least 4 weeks since prior radiotherapy to index lesion and recovered No prior radiotherapy to greater than 25% of red marrow No prior radiotherapy to maximum tolerated levels for any critical organ (e.g., lung, liver, or kidney) Surgery: At least 4 weeks since prior major surgery Other: No concurrent antiretroviral medication