Vaccine Therapy and Sargramostim in Treating Patients With Sarcoma or Brain Tumor

DISEASE CHARACTERISTICS: * Histologically or cytologically confirmed diagnosis of 1 of the following malignancies: * Stage III or IV sarcoma, including: * Leiomyosarcoma * Synovial cell sarcoma * Liposarcoma * Gastrointestinal stromal tumor * Brain tumor, including: * Diffuse pontine glioma\* * Glioblastoma multiforme * Glialsarcoma NOTE: \*For patients with diffuse pontine glioma, the requirement for histologic verification may be waived * No known curative therapy * HLA A\*0201 positive by genotyping PATIENT CHARACTERISTICS: Age * Over 2 Performance status * Karnofsky 60-100% (patients over age 16) * Lansky 60-100% (patients under age 16) Life expectancy * Not specified Hematopoietic * WBC greater than 3,000/mm\^3 * Absolute neutrophil count greater than 1,500/mm\^3 * Platelet count greater than 100,000/mm\^3 Hepatic * AST and ALT less than 2.5 times upper limit of normal (ULN) * Bilirubin less than 1.5 times ULN Renal * Creatinine less than 1.5 times ULN Cardiovascular * No clinically significant cardiovascular disease Pulmonary * No clinically significant pulmonary disease PRIOR CONCURRENT THERAPY: Biologic therapy * No prior hematopoietic stem cell transplantation * No other concurrent vaccine therapy * No other concurrent immunotherapy Chemotherapy * No prior chemotherapy * No concurrent chemotherapy Endocrine therapy * Concurrent dexamethasone allowed provided patient has been on a decreasing dose for the past 2 weeks and the current dose is the lowest clinically acceptable dose (ideally, less than 9-12 mg/day) Radiotherapy * No prior extensive-field radiotherapy that would compromise bone marrow function * At least 2 weeks since prior local radiotherapy Surgery * At least 2 weeks since prior surgery Other * At least 2 weeks since prior imatinib mesylate * No concurrent local anesthetic to administration site of vaccine