Retroperitoneal Sarcoma

Introduction

Retroperitoneal sarcomas account for 10% to 15% of adult soft tissue sarcomas, or about 1000 new cases each year. Patients have relatively poor survival rates because these tumors often do not produce symptoms until late in the disease. Retroperitoneal sarcomas can become quite large before symptoms begin; about half will exceed 20 cm at diagnosis.

Nonsurgically treated lymphoma should be ruled out in patients with retroperitoneal masses. Computed tomography (CT) scans should be performed to determine the extent of the tumor, show its relationship to surrounding structures, and identify possible distant metastases. CT-guided biopsy of the mass is the technique of choice for definitive diagnosis.

Complete margin-negative resection is the standard of care for retroperitoneal sarcoma. These tumors can invade surrounding organs, with kidney, colon, pancreas, and spleen most often involved. Also, these tumors create intense reactions in surrounding tissues; these reactions make it difficult to assess whether the tumors are invading, rather than just pushing on, surrounding structures.

Preoperative Imaging and Incision

The retroperitoneum has many vital structures, including the kidneys, pancreas, inferior vena cava (IVC), and the aorta (Fig. 50-1). These structures are close to each other and can become greatly distorted by a large retroperitoneal tumor. Preoperative imaging is particularly useful; the CT scan in Figure 50-1 shows a large, right retroperitoneal tumor. This tumor encroaches on the IVC and clearly involves the right kidney. Availability of this information before surgery can allow for preoperative assessment of kidney function in the event of nephrectomy and planning for possible vascular resection (consulting with vascular surgeon).