Treatment of Non-Hodgkin's Lymphoma With 90Y-hLL2 IgG

Inclusion: * Histological or cytological diagnosis of B-cell lymphoma, and has failed at least one regimen of standard chemotherapy. (All histological grades of NHL will be eligible for this trial.) * Measureable via CT, with at least one lesion \> or = 1.5cm in one or both dimensions. (Splenic tumors in absence of other tumors will not qualify.) * Radiological studies (ie - CT) must be performed within 4 weeks prior to study start. * Acceptable tumor burden that will allow adequate follow-up and evaluation. * Less that 25% bone marrow involvement, determined by bone marrow biopsy. * Must observe the following washout periods: At least 4 weeks beyond any major surgery. At least 4 weeks beyond any radiation therapy to the index lesion, and has recovered from radiation-induced toxicity. At least 4 weeks beyond chemotherapy and/or immunotherapy. At least 2 weeks beyond corticosteriod(s) use and blood counts are with laboratory criteria. * Must have Karnofsky score \>70% (or equivalent, ECOG 0-2) with expected survival of at least 6 months. * Serum creatinine \< or = 1.5mg/dl or creatinine clearance \> or = 50ml/min. * Serum bilirubin \< or = 2mg/dl. * Hemoglobin \> or = 10 g/dl; WBC \> or = 3000/mm3; granulocyte count \> or = 150/mm3; platelet count \> or = 100,000/mm3 with out transfusions or cytokines for at least 30 days prior to study. * Immunomedics ELISA assay of HahLL2 \< 100ng/ml for those with prior history of monoclonal antibody infusions. * Cognizant informed consent.