In 12 patients computed tomography revealed an unusual pattern of lymphomatous growth resulting in envelopment or engulfment of an organ. The kidneys were involved in eight cases, and the mediastinum and pericardium, oesophagus, stomach and rectosigmoid colon, and psoas muscle in one case each. Ten patients had non-Hodgkin's lymphoma and two had Hodgkin's disease; in every case, lymphomatous masses surrounded but did not destroy the affected tissues. The potential for both Hodgkin's and non-Hodgkin's lymphomas to enwrap both renal and non-renal tissues has not previously been emphasised.