Rituximab in Treating Patients With Refractory or Relapsed Primary CNS Lymphoma

You may be eligible if

• DISEASE CHARACTERISTICS:
• Histologically confirmed primary CNS lymphoma based on 1 of the following:
• * Histologically confirmed non-Hodgkin's B-cell lymphoma by brain biopsy or resection
• * Positive cerebrospinal fluid (CSF) cytology or immunohistochemical diagnosis of CSF monoclonality with or without measurable intracranial disease
• * Histologically confirmed vitreal lymphoma with measurable intracranial tumor
• CD20 positive by brain biopsy
• Measurable (greater than 1 cm in diameter) tumor by CT scan or MRI
• Progressed during first-line chemotherapy and/or radiotherapy OR relapsed after initial successful treatment
• No systemic lymphoma by CT scan of the chest, abdomen, and pelvis with contrast
• No leptomeningeal lymphoma by lumbar puncture for CNS cytology/flow cytometry
• No ocular lymphoma by slit lamp examination
• PATIENT CHARACTERISTICS:
• Age
• 18 and over
• Performance status
• Karnofsky 60-100%
• Life expectancy
• Not specified
• Hematopoietic
• Absolute neutrophil count at least 1,500/mm\^3
• Platelet count at least 100,000/mm\^3
• Hemoglobin at least 9.0 g/dL
• Hepatic
• Bilirubin less than 1.5 mg/dL
• Transaminases less than 4 times upper limit of normal
• Renal
• Creatinine less than 1.5 mg/dL
• Other
• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective contraception during and for 1 year after study participation
• HIV negative
• Mini mental status examination score at least 15
• No concurrent serious infection
• No other medical illness that would preclude study treatment
• No other malignancy within the past 5 years except curatively treated basal cell or squamous cell skin cancer or carcinoma in situ
• PRIOR CONCURRENT THERAPY:
• Biologic therapy
• More than 90 days since prior biologic therapy
• No prior rituximab
• No concurrent prophylactic growth factors (e.g., filgrastim \[G-CSF\] or sargramostim \[GM-CSF\])
• Chemotherapy
• See Disease Characteristics
• At least 3 weeks since prior chemotherapy (6 weeks for nitrosoureas)
• Endocrine therapy
• Not specified
• Radiotherapy
• See Disease Characteristics
• At least 3 months since prior radiotherapy
• Surgery
• Not specified
• Other
• Recovered from prior therapy
• More than 90 days since prior investigational drugs
• More than 90 days since prior use of a therapeutic device