OUTLINE: Patients receive gallium nitrate IV continuously on days 1-7. Courses repeat every 4 weeks in the absence of disease progression or unacceptable toxicity. Patients who achieve complete remission (CR) receive 2 additional courses past CR. Patients who relapse after achieving CR may be retreated in the absence of disease progression. Treatment for relapse after a second CR is at the discretion of the principal investigator. Patients with leptomeningeal disease at study entry must receive intrathecal (IT) methotrexate with IV leucovorin calcium or IT cytarabine. Patients who develop leptomeningeal disease while on study may continue treatment with gallium nitrate but must also receive IT methotrexate and leucovorin calcium (with or without radiotherapy) or IT cytarabine. Patients are followed for survival.