Pathology-proven diffuse large B-cell lymphoma with para-aortocaval lymphadenopathy causes a typical floating aorta sign and liver involvement.

The floating aorta sign refers to displacing the abdominal aorta away from the vertebral column by the retroperitoneal mass and most commonly suggests a lymphoma diagnosis.

Rarely, other diseases with diffuse retroperitoneal mass, such as Castleman's disease, primary retroperitoneal sarcomas, metastatic testicular cancer and tuberculous adenitis, may mimic a similar appearance.