Imatinib Mesylate in Treating Patients With Recurrent Malignant Glioma or Meningioma

DISEASE CHARACTERISTICS: * Histologically confirmed recurrent or unresectable malignant glioma * Glioblastoma multiforme (phase I only) * Anaplastic astrocytoma * Anaplastic oligodendroglioma * Anaplastic mixed oligoastrocytoma * Malignant astrocytoma not otherwise specified * Gliosarcoma * Low-grade histology with subsequent diagnosis of malignant glioma allowed (phase I only) OR * Histologically confirmed recurrent or unresectable benign or malignant meningioma (phase I only) * No prior intracranial hemorrhage * Failed prior radiotherapy * Progressive or recurrent disease by MRI or CT scan and/or resection * PET or thallium scan, MR spectroscopy, or surgical documentation required in patients who have received prior interstitial brachytherapy or stereotactic radiosurgery * Stable dose of steroids for 5-7 days prior to MRI or CT scan PATIENT CHARACTERISTICS: Age: * 18 and over Performance status: * Karnofsky 60-100% Life expectancy: * More than 8 weeks Hematopoietic: * Absolute neutrophil count at least 1,500/mm\^3 * Platelet count at least 100,000/mm\^3 * Hemoglobin at least 10 g/dL (transfusion allowed) Hepatic: * Bilirubin less than 2 times upper limit of normal (ULN) * SGOT less than 2 times ULN * No significant hepatic disease Renal: * Creatinine less than 1.5 mg/dL * Creatinine clearance at least 60 mL/min * No significant renal disease Cardiovascular: * No significant cardiac disease * No deep venous or arterial thrombosis within the past 6 weeks Pulmonary: * No pulmonary embolism within the past 6 weeks Other: * Not pregnant or nursing * Negative pregnancy test * Fertile patients must use effective barrier contraception during and for up to 6 months after study participation * No other serious concurrent medical illness * No serious active infection * No concurrent disease that would obscure toxicity or alter drug metabolism * No other malignancy within the past 3 years except nonmelanoma skin cancer or carcinoma in situ of the cervix PRIOR CONCURRENT THERAPY: Biologic therapy: * At least 1 week since prior interferon or thalidomide and recovered * No concurrent immunotherapy * No concurrent prophylactic filgrastim (G-CSF) Chemotherapy: * Recovered from prior chemotherapy * At least 4 weeks since prior cytotoxic therapy * At least 2 weeks since prior vincristine * At least 6 weeks since prior nitrosoureas * At least 4 weeks since prior temozolomide * At least 3 weeks since prior procarbazine * Prior polifeprosan 20 with carmustine implant (Gliadel wafer) allowed * Prior radiosensitizers allowed * No other concurrent chemotherapy * Phase I only: * Prior chemotherapy required for anaplastic astrocytoma, anaplastic oligodendroglioma, and anaplastic mixed oligoastrocytoma * Prior treatment for up to 3 relapses allowed * Phase II only: * Prior chemotherapy not required * Prior treatment for up to 2 relapses allowed Endocrine therapy: * See Disease Characteristics * At least 1 week since prior tamoxifen and recovered * No concurrent anticancer hormonal therapy Radiotherapy: * See Disease Characteristics * At least 4 weeks since prior radiotherapy * No concurrent radiotherapy Surgery: * See Disease Characteristics * Recovered from prior surgical resection of recurrent or progressive disease Other: * At least 1 week since prior non-cytotoxic agents and recovered * At least 1 week since prior tretinoin and recovered * At least 2 weeks since prior drugs that affect hepatic metabolism * No other concurrent investigational agents * No concurrent warfarin