DISEASE CHARACTERISTICS: Histologically confirmed recurrent soft tissue sarcoma Incompletely or completely resected metastatic or locally recurrent disease (surgery must be performed with intent of complete resection) No active brain metastases

PATIENT CHARACTERISTICS: Age: Over 18 Performance status: Karnofsky 70-100% Life expectancy: At least 16 weeks Hematopoietic: WBC at least 3,000/mm3 Absolute neutrophil count at least 1,000/mm3 Platelet count at least 80,000/mm3 Hepatic: Not specified Renal: Creatinine no greater than 2.5 mg/dL Cardiovascular: No New York Heart Association class III or IV heart disease Other: No active infections requiring antibiotics within 2 weeks of study No other serious medical illness requiring hospitalization No history of primary or secondary immunodeficiency or autoimmune disease No contraindications to MRI (e.g., aneurysm clips or cardiac pacemakers) Not pregnant or nursing Negative pregnancy test Fertile patients must use effective contraception

PRIOR CONCURRENT THERAPY: Biologic therapy: At least 6 weeks since prior immunotherapy and recovered Chemotherapy: At least 6 weeks since prior chemotherapy and recovered Endocrine therapy: No concurrent systemic corticosteroids Radiotherapy: At least 6 weeks since prior radiotherapy and recovered Surgery: See Disease Characteristics No prior splenectomy Other: At least 6 weeks since other prior experimental anticancer therapy and recovered No concurrent non-steroidal anti-inflammatory drugs or other immunosuppressive drugs No other concurrent participation in a clinical trial