Combination Chemotherapy With or Without Rituximab in Treating Patients With Mantle Cell Lymphoma

RATIONALE: Drugs used in chemotherapy use different ways to stop cancer cells from dividing so they stop growing or die. Monoclonal antibodies such as rituximab can locate cancer cells and either kill them or deliver cancer-killing substances to them without harming normal cells. It is not yet known if combination chemotherapy is more effective with or without rituximab in treating mantle cell lymphoma. PURPOSE: Randomized phase II trial to compare the effectiveness of fludarabine and cyclophosphamide combined with rituximab to that of fludarabine and cyclophosphamide alone in treating patients who have mantle cell lymphoma.