The patient was a 49 year old man with a 1 year history of left-sided lower abdominal pain and without renal symptoms. At necropsy he was found to have lymphosarcoma and bacterial endocarditis. The specimen consists of half a kidney measuring 14 x 7 x 4 cms. The cortex and pelvis of the kidney are largely replaced by white lymphomatous infiltration. The cortico-medullary junction can still be distinguished and there does not appear to be obvious infiltration of the medulla. The capsule strips with difficulty to reveal a finely granular surface.