Inclusion Criteria:

- Previously untreated patients with DLBCL of the breast.

- Patients must have CD20 positive tumors.

- Stage IE or IIE.

- Must have at least one objective measurable or evaluable disease. Baseline
measurements and evaluations must be obtained within 4 weeks of registration to the
study.

- Patients must not have historical or radiographic evidence of CNS metastasis
including previously treated, resected or asymptomatic brain lesions or
leptomeningeal involvement.

- Patients must have an ECOG performance status 0-2.

- Patients must have adequate organ function as evidenced by the following laboratory
studies (within 2 weeks prior to registration):

- Creatinine Clearance >= 50 ml/min

- Total bilirubin <= 2.0 mg/dl and AST <= 2 x upper limit of normal. If
documented hepatic involvement with lymphoma, total bilirubin can be <= 3 x
*ULN, and AST <= 5 x ULN.

- Absolute neutrophil count >= 1500/mm3 and platelet count >= 100,000/mm3. If
documented bone marrow involvement with lymphoma, absolute neutrophil count >=
500/mm^3 and platelet count >= 50,000/mm^3.

- Patients must be age >= 18 years.

- Women must not be pregnant or breast feeding due to potential harmful effects to the
fetus/baby. Women of childbearing potential and sexually active males are strongly
advised to use an accepted and effective method of contraception.

- Patients must not have an active infection requiring parental antibiotics.

- Patients with known HIV infection are excluded.

- Patients must have a normal left ventricular ejection fraction to be eligible.