Inclusion Criteria

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