Topotecan Hydrochloride in Treating Children With Meningeal Cancer That Has Not Responded to Previous Treatment

Inclusion Criteria: * Histologically proven refractory leukemia, lymphoma, or other solid tumor thathas overt meningeal involvement (Recurrent CNS acute lymphoblastic leukemia stratum only open to accrual as of 11/30/04) * Definition of meningeal disease: * Leukemia/lymphoma (including acute lymphoblastic leukemia) * CSF cell count greater than 5/mm\^3 AND evidence of blast cells oncytospin preparation or by cytology * Refractory to conventional therapy, including radiotherapy (i.e., in second or greater relapse) * No concurrent bone marrow relapse * Solid tumors (including medulloblastoma) * Presence of tumor cells on cytospin preparation or cytology OR presence ofmeningeal disease on MRI scans * No clinical evidence of obstructive hydrocephalus or compartmentalization ofCSF flow as documented by radioisotope indium In 111 or technetium Tc 99 DTPAflow study * If CSF flow block is demonstrated, focal radiotherapy must be administered tosite of block to restore flow and a repeat CSF flow study must show clearing of blockage * No ventriculoperitoneal or ventriculoatrial shunt unless: * Patient is shunt independent and there is evidence that the shunt is nonfunctional * CSF flow study demonstrates normal flow * No impending cord compression, CNS involvement requiring local radiotherapy(e.g., optic nerve), or isolated bulky ventricular or leptomeningeal basedlesions * Performance status - Lansky 50-100% (age 10 and under) * Performance status - Karnofsky 50-100% (over age 10) * At least 8 weeks * Platelet count greater than 40,000/mm\^3 (transfusions allowed) * Bilirubin less than 2.0 mg/dL * SGPT less than 5 times normal * Creatinine less than 1.5 mg/dL * Electrolytes, calcium, and phosphorus normal * Not pregnant or nursing * Negative pregnancy test * Fertile patients must use effective contraception * No significant illness (e.g., uncontrolled infection, except HIV \[i.e., AIDS-related lymphomatous meningitis\]) * Prior immunotherapy allowed and recovered * At least 3 weeks since systemic CNS directed chemotherapy (6 weeks for nitrosoureas) and recovered * At least 1 week since prior intrathecal (IT) chemotherapy (2 weeks for cytarabine \[liposomal\]) * No prior IT chemotherapy on days -14 to -7 before study entry unless evidence of disease progression (e.g., increasing WBC and percentage blasts in patients with leukemia/lymphoma or increased leptomeningeal enhancements in patients with solid tumors) (Recurrent CNS acute lymphoblastic leukemia stratum only open to accrual as of 11/30/04) * Concurrent chemotherapy to control systemic disease or bulk CNS disease allowed if the systemic chemotherapy is not a phase I study agent that significantly penetrates the CSF (e.g., high-dose systemic methotrexate \[greater than 1 g/m\^2\], thiotepa, high-dose cytarabine, temozolomide, IV mercaptopurine, nitrosourea, or topotecan) or an agent known to have serious unpredictable CNS side effects * Concurrent dexamethasone or prednisone allowed if part of a systemic chemotherapy regimen * See Disease Characteristics * At least 8 weeks since prior cranial irradiation and recovered * No concurrent whole brain or craniospinal irradiation * At least 7 days since prior investigational drug * Time period should be extended if patient has received any investigational agent that is known to have delayed toxic effects after 7 days or a prolonged half-life * No other concurrent investigational agents * No concurrent therapy (IT or systemic) for leptomeningeal disease * No other concurrent systemic agents that significantly penetrate the blood-brain barrier