Figure 3: Axial contrast enhanced CT images of the abdomen in a 63-year-old male with retroperitoneal liposarcoma at baseline (a) and following 5 months therapy (b). Although the well-differentiated component filling the left side of the retroperitoneum (*) showed little change, the dedifferentiated component (arrows) surrounding the aortic bifurcation reduced in size from 7.9 cm to 2.5 cm (PR).