A case of an adult patient with ileocolic intussusception secondary to a lymphoma of the terminal ileum is reported. On the computed tomograms, a target mass, with the outer rim representing the annular tumour of the terminal ileum and the eccentric rim of low attenuation representing the mesentery, is described. Ultrasound patterns are those of parallel hypoechoic areas separated by hyperechoic stripes seen on longitudinal sections, and of a rounded mass of low echogenicity, exhibiting two hyperechoic concentric ring-like areas within it, on transverse scans. The appearances of the barium examinations are also described. The English literature is reviewed.