Diffuse invasive signet ring cell carcinoma in total colorectum caused by ulcerative colitis: A case report and review of literature

Figure 1 Preoperative colonoscopy. The surface showed nodular or cauliflower-like changes; the rectal mucosa was congested and showed edema; the surface showed longitudinal changes, with many scattered small ulcers and a little mucus-like white coating on the surface or a small amount of bleeding. The intestinal cavity was so narrow that the endoscope was unable to pass.