There is a relatively well-defined large heterogeneous enhancing soft tissue mass lesion in the left retroperitoneal region, with the following characteristics: it extends just below the inferior pole of the left kidney (but there is no communication with it), it reaches the left pelvis and splays the left psoas and iliacus muscles (there is an area that is inseparable from the mass which may suggest left psoas muscle invasion). It measures maximally 8 x 11 x 13 cm in three dimensions. It is surrounded by minimal stranding of fat planes. There is no vascular encasement. There is no associated lymph node enlargement. There is no bony involvement or extension of the spinal canal or exit foramina. The mass doesn't contain any fat elements. There is no ascites.
The rest of the abdominal visceral organs are unremarkable.