A case of chronic ulcerative colitis is reported in which a carcinoma developed 17 years after onset of the disease. The patient was treated with a radical subtotal colectomy and ileostomy. The pathological report confirmed the presence of a 3 cm., well-differentiated carcinoma of the right transverse colon with 59 negative lymph nodes. The patient died six weeks following operation with widespread metastatic disease, confirmed at autopsy. The purpose in again discussing neoplasia in chronic ulcerative colitis is to reiterate the virulence of the cancer, even in the presence of negative lymph nodes; to point out the gravity of shedding viable cancer cells, especially in the presence of a nourishing incubating medium, such as ascitic fluid, and to discuss the remarkable capacity for malignant-cell transplantation of a patient with ulcerative colitis without a spleen. Report of Case A 32-year-old itinerant waiter who had a history of ulcerative colitis for 17