[Imaging of renal graft lymphomas. Apropos of 5 cases]

The occurrence of non-hodgkin's lymphoma is a classical complication after transplantation. The frequent localization near the graft is well established. We report 5 cases of lymphoma, arising from the renal graft, from a series of 648 transplantations (0.77%). The lesions appear as soft tissue masses, iso or hypoechoic with ultrasonography, soft tissue attenuation with CT and low attenuation after contrast medium. With MRI, we note isosignal in T1 and hyposignal in T2 weighted sequences. The involvement of renal parenchyma (n = 3) and the inclusion of the vessels in the masses (n = 2) are frequent. Excretory tract compression leading to obstruction is often associated (n = 3).