PATIENT CHARACTERISTICS: Age: 18 and over Performance status: ECOG 0-2 Life expectancy: At least 1 year Hematopoietic: Absolute lymphocyte count greater than 5,000/mm3 Mature lymphocytes with less than 55% prolymphocytes, atypical lymphocytes, or lymphoblasts Bone marrow with at least 30% lymphocytes Hepatic: No cirrhosis Renal: Not specified Cardiovascular: No history of unstable cardiac arrhythmia No active congestive heart failure Other: No history of uncontrolled seizure disorder Not pregnant or nursing Negative pregnancy test Fertile patients must use effective contraception No other concurrent condition that would make life expectancy less than 1 year