Figure 2.

Axial (a) and coronal (b) contrast enhanced CT of the abdomen in a patient with chronic lymphocytic leukemia displaying encasement of vessels such as the left renal vein (white arrow) and right renal artery (black arrow) by lymph nodes masses, the so-called “sandwich sign.” Axial contrast enhanced CT (c) of the abdomen at a lower level in the same patient displaying elevation of the abdominal aorta off the vertebral column (white arrow) which is a characteristic feature of lymphoma and helps to differentiate lymphoma from other retroperitoneal masses, such as retroperitoneal fibrosis. Note the encasement of the superior mesenteric artery (SMA) by the lymph node mass and increased separation of the SMA from the aorta (black arrow).