DISEASE CHARACTERISTICS:

• Histologically confirmed newly diagnosed follicular B-cell lymphoma

  • CD20-positive disease
• Measurable disease, defined as ≥ 1 unidimensionally measurable lesion ≥ 20 mm by conventional techniques OR ≥ 10 mm by spiral CT scan
• No known brain metastases

PATIENT CHARACTERISTICS:

• ECOG performance status (PS) 0-2 OR Karnofsky PS 70-100%
• WBC ≥ 3,000/mm³
• Absolute neutrophil count ≥ 1,500/mm³
• Platelet count ≥ 100,000/mm³
• Hemoglobin ≥ 8.0 g/dL
• Bilirubin normal
• AST and ALT ≤ 2.5 times upper limit of normal
• Creatinine normal OR creatinine clearance ≥ 60 mL/min
• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective contraception
• No history of allergic reactions attributed to compounds of similar chemical or biological composition to rituximab or other agents (e.g., sargramostim [GM-CSF] or yeast-derived components of the recombinant) used in the study
• No known anaphylaxis or IgE-mediated hypersensitivity to murine proteins

• No uncontrolled intercurrent illness, including, but not limited to, any of the following:

  • Ongoing or active infection
  • Symptomatic congestive heart failure
  • Unstable angina pectoris
  • Cardiac arrhythmia
  • Psychiatric illness or social situation that would preclude study compliance

• No evidence of active or prior infection with hepatitis B

  • Patients vaccinated for hepatitis B who have positive antibodies allowed

PRIOR CONCURRENT THERAPY:

• No prior therapy for follicular B-cell lymphoma
• No other concurrent investigational agents
• No concurrent combination antiretroviral therapy for HIV-positive patients
• No concurrent steroids, including dexamethasone or other glucocorticoids
• No concurrent pegfilgrastim or other long-acting colony-stimulating factor
• No concurrent cytotoxic therapy
• No other concurrent anticancer agents or therapies