DISEASE CHARACTERISTICS: Histologically proven newly diagnosed or relapsed non-Hodgkin's lymphoma (NHL) of 1 of the following types: Low grade (diffuse small lymphocytic/marginal zone, grade I follicular small cleaved cell, or grade II follicular mixed cell) OR Mantle cell OR Histologically proven newly diagnosed or relapsed stage III or IV chronic lymphocytic leukemia (CLL) or prolymphocytic leukemia (PLL) At least 1 measurable disease parameter Enlarged spleen extending at least 2 cm below the costal margin constitutes measurable disease provided that no explanation other than lymphomatous involvement is likely Enlarged liver extending at least 5 cm below the costal margin constitutes measurable disease Not allowable as sole indication for therapy: Isolated splenomegaly OR Isolated hepatomegaly No central nervous system (CNS) metastases or carcinomatous meningitis A new classification scheme for adult non-Hodgkin's lymphoma has been adopted by PDQ. The terminology of "indolent" or "aggressive" lymphoma will replace the former terminology of "low", "intermediate", or "high" grade lymphoma. However, this protocol uses the former terminology.