Figure 1: (a, b) Computed tomography (a: sagittal and b: Axial view), showing the septate, predominantly cystic retroperitoneal mass from the iliac crest to the diaphragm; there are few solid, enhancing areas. Note the medially displaced left kidney (long arrow), aorta (short arrow) and inferior vena cava (arrowhead); (c) Macroscopic examination showed an encapsulated, well-circumscribed mass; (d) The cut section was variegated