Inclusion Criteria

DISEASE CHARACTERISTICS:

- Histologically confirmed diffuse large B-cell non-Hodgkin's lymphoma, including any
of the following:

- B-cell diffuse large cell variant

- Immunoblastic

- Mediastinal (thymic) large cell

- T-cell/histiocyte-rich

- Anaplastic large B-cell

- Intravascular large B-cell

- Lymphomatoid granulomatosis

- Relapsed or refractory disease after at least 1 prior chemotherapy regimen and
requires further treatment

- Relapsed disease, defined as the following:

- Appearance of any new lesion OR increase of at least 50% in the size of a
previously involved site

- 50% increase in greatest diameter of any previously identified node greater
than 1 cm in the short axis OR in the sum of the perpendicular diameter
(SPD) of more than 1 node

- Progressive disease, defined as the following:

- 50% increase from nadir in the SPD of any previously identified abnormal
node

- Appearance of any new lesion during or at the end of therapy

- CD20-positive disease by immunohistochemistry

- Bidimensionally measurable disease

- At least 1 lesion at least 2.0 cm by CT scan

- Less than 25% bone marrow involvement by lymphoma

- No transformed lymphoma from indolent to aggressive

- No HIV- or AIDS-related lymphoma

- No hypocellular bone marrow

- No marked reduction in bone marrow precursors of 1 or more cell lines (e.g.,
granulocytic, megakaryocytic, or erythroid)

- No CNS lymphoma

- Ineligible for myeloablative therapy OR refused transplantation

- Ineligible for any other open yttrium Y 90 ibritumomab tiuxetan investigational
protocols

PATIENT CHARACTERISTICS:

Age

- 18 and over

Performance status

- WHO 0-2

Life expectancy

- At least 3 months

Hematopoietic

- Absolute neutrophil count at least 1,500/mm^3

- Lymphocyte count no greater than 5,000/mm^3 (for patients with small lymphocytic
lymphoma)

- Platelet count at least 100,000/mm^3

Hepatic

- Bilirubin no greater than 2.0 mg/dL

Renal

- Creatinine no greater than 2.0 mg/dL

Other

- Not pregnant or nursing

- Negative pregnancy test

- Fertile patients must use effective contraception during and for 1 year after study
participation

- No concurrent serious nonmalignant disease or infection that would preclude study
participation

- No human antimurine antibody reactivity

PRIOR CONCURRENT THERAPY:

Biologic therapy

- See Disease Characteristics

- No prior autologous bone marrow transplantation

- No prior peripheral blood stem cell rescue

- No prior failed stem cell collection

- Prior rituximab within the past 90 days allowed provided patient has
fludeoxyglucose-avid disease that is also indium In 111 ibritumomab tiuxetan-avid
disease in at least 1 lesion

- More than 2 weeks since prior filgrastim (G-CSF) or sargramostim (GM-CSF)

Chemotherapy

- See Disease Characteristics

Endocrine therapy

- Not specified

Radiotherapy

- No prior radioimmunotherapy

- No prior external beam radiotherapy (involved field or regional) to more than 25% of
active bone marrow

Surgery

- More than 4 weeks since prior major surgery (except diagnostic surgery)

Other

- Recovered from all prior therapy

- More than 4 weeks since prior therapy for lymphoma

- More than 8 weeks since prior phase II investigational drugs

- No other concurrent antineoplastic therapy