DISEASE CHARACTERISTICS:

* Histologically confirmed diagnosis of T-cell acute lymphoblastic leukemia (ALL) or lymphoblastic lymphoma (LBL)
* Leukemia or lymphoma cells should express at least two of the following cell surface antigens: CD1a, CD2, CD3 (surface or cytoplasmic), CD4, CD5, CD7, and CD8
* Leukemia cells should be negative for myeloperoxidase or Sudan Black B If the only T cell markers present are CD4 and CD7, the leukemic cells should be demonstrated to lack the myeloid markers CD33 and/or CD13
* Refractory to at least one induction treatment regimen or in first or later relapse after achieving a complete remission
* No CNS leukemia or lymphoma requiring intrathecal or craniospinal radiotherapy

PATIENT CHARACTERISTICS:

* Age: 16 and over
* Bilirubin no greater than 2 times upper limit of normal (unless due to leukemia)
* Creatinine clearance at least 50 mL/min (unless due to leukemia)
* No neurologic toxicity of grade 3 or greater during prior treatment of ALL/LBL
* No preexisting neuropathy of grade 2 or greater regardless of causality
* No history of seizure disorder
* Not pregnant or nursing
* Fertile patients must use effective contraception

PRIOR CONCURRENT THERAPY:

* No concurrent erythropoietin
* No other concurrent chemotherapy
* No concurrent dexamethasone or other steroidal antiemetics
* No concurrent hormone therapy, except for non-disease-related conditions