OUTLINE: Patients are stratified according to interleukin-2 receptor classification (positive vs negative). Patients receive immunotoxin therapy with denileukin diftitox IV over 15-60 minutes on days 1-5. Treatment repeats every 21 days for 2-6 courses in the absence of disease progression or unacceptable toxicity. Patients are followed every 3 months for 2 years, every 6 months for 3 years, and then annually thereafter.