OUTLINE: This is a two arm, escalating dose study of interleukin-2 (IL-2). In Arm I patients in cohorts of 3-6 are administered daily inhalations of IL-2 over 15 minutes on Monday through Friday for 4 consecutive weeks. At least 3 patients are treated at each dose level, and all patients in a cohort are observed for at least 2 weeks before escalating to a higher dose in absence of dose limiting toxicity. Escalation stops when maximum tolerated dose (MTD) is determined. In Arm II the initial dose is 25 percent of the MTD determined in Arm I administered by inhalation twice daily on Monday through Friday for 4 weeks. Subsequent patient cohorts receive doses escalated by 33 percent above the previous dose level. Responding patients continue treatment cycles of 4 weeks with 2 weeks of rest until they develop progressive disease or intolerable toxicity. Stable patients may stay on treatment for a maximum of 4 cycles.