retroperitoneal sarcomaA nonspecific term for any sarcoma arising in the retroperitoneal region, which comprises 15% of all sarcomas (of 8,600 cases/year, USA).
Often asymptomatic abdominal mass; average age, 50.
65% to 80% of cases achieve complete resection; 5-year local recurrence, ±50%; 5-year survival, ±50%.
Histological types of retroperitoneal sarcoma
• Malignant fibrous histiocytoma (MFH)—7%;
• Fibrosarcoma—6% (MFH and fibrosarcoma are now viewed as synonyms);
• Malignant peripheral nerve sheath tumour—3%.