Purpose To retrospectively review CT and MRI findings of spinal epidural lymphoma(SEL)in twelve patients to find out their radiological features.Methods CT and MRI findings of twelve patients with pathologically proved spinal epidural lymphoma,including of five cases of primary spinal epidural lymphoma(PSEL)and seven cases of secondary spinal epidural lymphoma(SSEL),were retrospectively reviewed.The tumor location,soft tissue mass,margin,signal intensity,necrosis,enhancement,bone destruction on CT and MRI imaging,involvement of vertebral appendix and intervertebral disc,and spinal cord compression were described.The main MR imaging features of the PSEL were compared with that of the SSEL.Results Five cases occurred in thoracic vertebra and seven in lumbar vertebra.All cases had epidural and paraspinal soft tissue mass with average size of 0.88×4.81cm2 and 1.35×3.33cm2,respectively.Most lesions were well-defined.Comparing with the spinal cord,the epidural lesions had isointense on T1-weighted imaging and iso-or mild hyper-intense on T2-weighted imaging.And most epidural lesions showed homogenous signal in all sequence and homogenous enhancement after administration of contrast agent.On CT images,there was no bony change in seven cases,osteolytic destruction in three cases and increased density of vertebral body in two cases.However,on MR images,except one case with no bony change,other eleven cases were all observed signal change with hypointense on T1-weighted imaging and hypo-or hyper-intense on T2-weighted imaging.After contrast enhancement,the involved vertebral were heterogeneously enhanced.Necrosis was found in epidural lesions of two cases and in paravertebral mass of two cases.In addition,the vertebral attachments were all involved.However except one case with compressive fracture,the vertebra body and intervertebral disc of the other cases did not involved.The spinal cord mostly suffered marked compression.The uniformity enhancement of involved vertebral body showed significant difference between PSEL and SSEL(P<0.05),but the other main MRI features showed no significant difference(P>0.05).Conclusions Spinal epidural lymphoma had some but not specific radiological features,it could be suggested when MR imaging showed an epidural well-defined mass with larger vertical diameter on sagittal view,and extending through the vertebral foraminal to invade paraspinal soft tissues with or without bony change,especially when MR imaging showed infiltrating bony destruction which was not seen on CT images.However,it is difficult to differentially diagnose PSEL from SSEL.The heterogeneous enhancement of the involved vertebral body on MR imaging may be helpful to identify them.