OUTLINE: This is a dose escalation study. Patients are stratified into risk groups (high vs low). Patients receive pretherapy imaging with indium In 111 humanized LL2 IgG IV for up to 30 minutes on days -7 to 0. Patients receive yttrium Y 90-labeled humanized anti-CD22 monoclonal antibody LL2 (90Y-hLL2-IgG) IV for up to 30 minutes on day 0. Cohorts of 3-6 patients receive escalating doses of 90Y-hLL2-IgG until the maximum tolerated dose (MTD) is determined. The MTD is defined as the dose preceding the dose at which 2 of 3 or 2 of 6 patients experience dose limiting toxicity. Patients are followed every 2 weeks for 1 month, monthly for 2 months, and then every 6 months thereafter.