DISEASE CHARACTERISTICS:

• Diagnosis of Waldenstrom's macroglobulinemia
• CD20 positive by bone marrow immunohistochemistry or flow cytometry
• Presence of monoclonal paraprotein
• IgM level at least 2 times upper limit of normal (ULN)

PATIENT CHARACTERISTICS:

Age:

• Over 18

Performance status:

• ECOG 0-2

Life expectancy:

• At least 6 months

Hematopoietic:

• Absolute neutrophil count greater than 1,000/mm^3
• Platelet count greater than 25,000/mm^3

Hepatic:

• Bilirubin less than 2.5 times ULN
• SGOT less than 2.5 times ULN

Renal:

• Creatinine less than 2.5 mg/dL

Other:

• Not pregnant or nursing
• Fertile patients must use effective contraception during and for 6 months after study
• No serious comorbid disease
• No uncontrolled bacterial, fungal, or viral infection
• No other active malignancy

PRIOR CONCURRENT THERAPY:

Biologic therapy:

• No prior rituximab
• No prior nucleoside analogue therapy

Chemotherapy:

• At least 30 days since prior chemotherapy

Endocrine therapy:

• At least 30 days since prior steroid therapy
• No concurrent corticosteroids

Radiotherapy:

• At least 30 days since prior radiotherapy

Surgery:

• Not specified

Other:

• No more than 2 prior courses of therapy