Intensive Chemotherapy and Rituximab in the Treatment of Burkitt Lymphoma

Inclusion Criteria: * Histologically documented Burkitt or atypical Burkitt according to World Health Organization (WHO) criteria. * Pathology must be reviewed at the Brigham and Women's Hospital (BWH). * Measurable or evaluable disease: Disease reproducibly measurable in two perpendicular dimensions on exam, computed tomography (CT), radiograph, or magnetic resonance imaging (MRI). Disease present on bone marrow biopsy will be considered as evaluable disease. * The following may not be used as the sole site of measurable or evaluable disease: \*ascites, \*pleural effusion, \*bone lesion or \*central nervous system (CNS) disease. * Age \> 18 * Laboratory data (within 2 weeks of study registration): * ANC \> 1500/ul; * platelet \> 100,000/ul; * creatinine \< 1.5 X normal; * creatinine clearance \> 60 ml/min; * bilirubin \< 1.5 X normal; * AST and ALT \< 2.5 X normal; * alkaline phosphates \< 3 X normal; * HIV negative; * cardiac ejection fraction \> 50%. Exclusion Criteria: * Previous chemotherapy or radiation therapy. Steroids of less than 72 hours duration for impending oncologic emergency are allowed. * Uncontrolled bacterial, fungal, or viral infection. * Concomitant malignancy excluding carcinoma in situ of the cervix and basal cell carcinoma of the skin. * Serious comorbid disease. Clinically significant pulmonary symptomatology. In patients with a history of symptomatic pulmonary disease, pulmonary function tests (PFTs) should document an forced expiratory volume at 1 second (FeV1), forced vital capacity (FVC), and total lung capacity (TLC) of \> 60% predicted and carbon monoxide diffusing capacity of the lung (DLCO) of \> 50% predicted. No clinically significant cardiac symptomatology. The cardiac ejection fraction must be \> 50%. * Pregnancy. All males and females with reproductive potential must consent to use an effective form of contraception while on study. * Major surgery within the previous 2 weeks.