Imatinib Mesylate and Hydroxyurea in Treating Patients With Recurrent or Progressive Meningioma

DISEASE CHARACTERISTICS: * Histologically confirmed meningioma * Recurrent or progressive disease after prior surgical resection * Measurable disease by contrast-enhanced MRI * Multifocal disease allowed * No evidence of intratumor hemorrhage on pretreatment diagnostic imaging * Stable postoperative grade 1 hemorrhage allowed * No peripheral edema or central or systemic fluid collections ≥ grade 2 (e.g., pericardial effusion, pulmonary effusion, ascites) PATIENT CHARACTERISTICS: * Karnofsky performance status 70-100% * Absolute neutrophil count \> 1,500/mm³ * Hemoglobin \> 9 g/dL * Platelet count \> 100,000/mm³ * Potassium normal\* * Calcium normal\* * Magnesium normal\* * Phosphorus normal\* * alanine aminotransferase (AST) and alanine aminotransferase (ALT) \< 2.5 times upper limit of normal (ULN) * Bilirubin \< 1.5 times ULN * Creatinine \< 1.5 times ULN OR creatinine clearance \> 50 mL/min * Not pregnant or nursing * Negative pregnancy test * Fertile patients must use effective contraception * No excessive risk of bleeding, as defined by stroke within the past 6 months * No active systemic bleeding (i.e., gastrointestinal bleeding or gross hematuria) * No history of central nervous system (CNS) or intraocular bleeding or septic endocarditis * No concurrent severe and/or uncontrolled medical disease, including any of the following: * Uncontrolled diabetes * Congestive cardiac failure * Myocardial infarction within the past 6 months * Poorly controlled hypertension * History of labile hypertension * History of poor compliance with antihypertensive regimen * Chronic renal disease * Active uncontrolled infection requiring intravenous antibiotics * No acute or chronic liver disease (i.e., hepatitis, cirrhosis) * No HIV positivity * No impairment of gastrointestinal function or disease that may significantly alter the absorption of imatinib mesylate, including any of the following: * Ulcerative disease * Uncontrolled nausea * Vomiting * Diarrhea * Malabsorption syndrome * Bowel obstruction * Inability to swallow tablets * No other malignancy within the past 5 years except basal cell skin cancer or cervical carcinoma in situ NOTE: \*Unless correctable with supplements PRIOR CONCURRENT THERAPY: * See Disease Characteristics * Recovered from prior therapy * More than 1 week since prior tumor biopsy * More than 2 weeks since prior surgical resection * Prior hydroxyurea allowed provided patient has not had progressive disease or toxicity \> grade 3 * No prior imatinib mesylate or other platelet-derived growth factor-directed therapy * At least 4 weeks since prior chemotherapy (6 weeks for nitrosoureas)\* * Chemotherapeutic agents such as etoposide that are normally given at shorter intervals allowed even if \< 4 weeks from last prior dose of chemotherapy * At least 4 weeks since prior radiotherapy\* * At least 1 week since prior biological, immunotherapeutic, or cytostatic drugs * At least 2 weeks since prior investigational drugs * No concurrent warfarin NOTE: \*Unless there is unequivocal evidence of tumor progression