We present the case of a patient presenting at the emergency department with subacute low back pain radiating to both lower limbs in whom ultrasonography and abdominal computed tomography diagnosed a retroperitoneal adenopathic mass compressing the inferior vena cava. Magnetid resonance imagin of the lumbar spine showed the retroperitoneal mass and also showed dilatation and tortuosity of the vessels of the lumbar epidural venous plexus, which was considered responsible for the radiating low back pain. Histological study defined the retroperitoneal mass as follicular non-Hodgkin's lymphoma. The dilatation of the lumbar epidural venous plexus can cause lumbar and radicular pain.