DISEASE CHARACTERISTICS: Histologically proven recurrent or refractory leukemia, lymphoma, or other solid tumor that has overt meningeal involvement Definition of meningeal disease: Leukemia/lymphoma: CSF cell count at least 5/mm3 and evidence of blast cells on cytospin preparation or cytology Solid tumors: Presence of tumor cells on cytospin preparation or cytology OR evidence of meningeal disease on CT or MRI scan No bone marrow disease