Although general or multicentric lymphosarcoma is well known, focal or unicentric lymphosarcoma has only recently become well understood. Ackerman and del Regato (1) in their textbook on cancer state: “Lymphosarcoma is often seen first as a generalized process, but a certain unknown but increasing proportion of cases has been reported with a definite focus of origin. Regato (1939) reported that lymphosarcoma frequently arose from the region of Waldeyer's ring (nasopharynx, tonsil, base of the tongue). The second most common location is from the gastrointestinal tract, from the stomach, large bowel or small bowel.” Sugarbaker and Craver (11), reviewing 196 proved cases of lymphosarcoma, found that 5.5 per cent arose in the digestive tract, over half of these having their origin in the stomach. One-third of their series appeared to arise primarily outside the lymphatic system. Such extra-nodal involvement appears to be worthy of attention. The roentgen manifestations of lymphosarcoma of the stomach have been reviewed by us in a previous paper (5). Here we shall confine ourselves to the manifestations in the small intestine. Incidence The exact incidence of lymphosarcoma of the small intestine is not known. Berman and Mainella (2), in 1945, quoted Charache as saying that he knew of 404 cases of intestinal lymphosarcoma. Menne, Mason, and Johnston (8) found 2 examples in 40,000 pathological examinations. Their review of the literature in 1942 yielded only 376 authentic cases of lymphosarcoma of the small intestine. Feldman (6) collected 58 cases of sarcoma of the small bowel from 104,621 necropsies. Lymphosarcoma has been reported in all parts of the intestinal tract. In the small bowel, the ileum is the most common site and the duodenum the least common. This incidence appears to parallel the richness of the lymphatic tissue in the gut. Lesions have been reported in the colon, especially in the rectal region. Most of the patients have been in the earlier decades of life, especially between the ages of twenty and forty (13). Cutler, Stark and Scott (4) feel that a neoplasm of the intestinal tract in an infant or child should be regarded as lymphosarcoma until proved otherwise. Roentgen manifestations In 1932 Ullman and Abeshouse (12) reported a case of lymphosarcoma of the ileum found unexpectedly during an operation for removal of the appendix. This lesion took the form of an annular constricting ring in the terminal ileum 12 cm. from the ileocecal valve, and was accompanied by two abscesses in the adjacent mesentery. These writers felt that an annular growth was the most common manifestation of the disease in the intestine and that symptoms and roentgen findings would be predominantly those of obstruction. This was true in Case IV of the series to be reported here. Present (9) in 1939 reported 2 cases of primary lymphosarcoma of the duodenum in which the roentgen findings were destruction and obliteration of the mucous membrane pattern, stiffening of the walls, and absence of peristalsis.