DISEASE CHARACTERISTICS: Histologically confirmed supratentorial anaplastic glioma with a recurrent cyst requiring aspiration for symptom control Measurable cystic lesion confirmed by contrast-enhanced CT or MRI At least 3 months since radiotherapy to site of measurable disease unless unequivocal evidence of tumor progression Neoplastic cell reactivity with tenascin demonstrated by immunohistology with either a polyclonal rabbit antibody or a monoclonal murine antibody

PATIENT CHARACTERISTICS: Age: 3 and over Performance status: Karnofsky 50-100% Hematopoietic: Absolute neutrophil count greater than 1,000/mm3 Platelet count greater than 100,000/mm3 Hepatic: Bilirubin less than 1.5 mg/dL AST less than 1.5 times normal Alkaline phosphatase less than 1.5 times normal Renal: Creatinine less than 1.2 mg/dL Other: Negative pregnancy test Effective contraception required of fertile women

PRIOR CONCURRENT THERAPY: Biologic therapy: Not specified Chemotherapy: At least 6 weeks since antineoplastic chemotherapy unless unequivocal evidence of tumor progression Endocrine therapy: Corticosteroids allowed if at lowest possible dose and dose stable for at least 10 days prior to entry Radiotherapy: See Disease Characteristics Surgery: Not specified