Rituximab Combined With Chemotherapy in Burkitt's Lymphoma

Inclusion Criteria: * Patients diagnosed with mature LLA-B cell (LLA-L3) * Patients diagnosed with Burkitt´s and Burkitt´s Like Lymphoma * Patients 15 years old or up * Written Informed Consent signed Exclusion Criteria: * Serious complications related with LAL3/LB or Secondary illness: Serious complications, uncontrollable, for example, sepsis, pneumonia with hypoxia, shock, haemorrhage at diagnosis. * Renal failure unconditional for the Lymphoma/Leukemia * Heart failure or serious liver. * Pulmonary obstructive disease or serious restrictive that not allow to treat the patient with intensive chemotherapy. * Secondary Lymphoma after chemotherapy or previous radiotherapy or second malignant tumour. * Known hypersensitivity to any foreign protein. * Previous treatment with cytostatics of the LLA-B or Burkitt´s Lymphoma (exception: administration on short time of glucocorticoids ≤ 7 days, one administration of vincristine or cyclophosphamide, one cycle of CHOP, urgent administration of the another cytostatics). * With another malignant tumour in the last 5 year. * Women in fertile age must give positive in the pregnancy test or nursing mother. * Mental disability or emotional or psychiatric significant disorder were the patient can't understand nor cooperate with treatment. * Patients is enrolled in another clinical research study.