OUTLINE: This is a dose escalation study. Patients receive a single dose of intravenous iodine I 131-labeled monoclonal antibody muJ591 on day 0, combined with an unlabeled (cold) dose of monoclonal antibody muJ591. Anterior and posterior imaging is obtained 1 hour after labeled muJ591 administration and on days 0, 2, 4, and 6. Subsequent cohorts of 3-6 patients receive fixed iodine-labeled doses with escalating cold doses of monoclonal antibody muJ591 until the maximum tolerated dose is reached. Patients are followed for a minimum of 8 weeks after muJ591 therapy or until disease progression. Patients with stable or responding disease who are human anti-mouse antibody negative may receive subsequent treatments at the discretion of the principal investigator.