Sarcomas are relatively rare malignant tumors that arise from mesenchymal cells and therefore encompass a variety of histologies and can occur in any anatomic compartment. The incidence of sarcoma is estimated at 1% of all new cancer diagnoses in the United States annually. Approximately 15% of soft tissue sarcomas occur in the retroperitoneum, with about 1600 new retroperitoneal sarcoma cases diagnosed in the United States each year.
