Continuous Intraventricular Methotrexate in Treating Patients With Leptomeningeal Disease

Inclusion Criteria: * Subjects with leptomeningeal carcinomatosis (from solid tumors) * Subjects with lymphomatous or leukemic meningitis * The effects of methotrexate on the developing fetus are unknown; for this reason, women of child-bearing potential and men must agree to use adequate contraception (hormonal or barrier method of birth control or abstinence) prior to study entry and for six months following the conclusion of study participation; should a woman become pregnant or suspect that she is pregnant while participating on the trial, she will be excluded from the study and should inform her treating physical immediately * Karnofsky Performance Status greater than 70% * All subjects must have the ability to understand and the willingness to sign a written informed consent * We will exclude subjects who have had prior intrathecal/intraventricular therapy with methotrexate within 6 months Exclusion Criteria: * Prior therapy with methotrexate for management of leptomeningeal disease * Subjects with evidence of hydrocephalous * Subjects with intraparenchymal lesions or bulky disease * Subjects with ventriculoperitoneal shunt in place * Previous history of whole brain radiation therapy * Subjects who, in the opinion of the principal investigator, may not be able to comply with the safety monitoring requirements of the study will not be included in this trial