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

Figure 4 Postoperative pathological section. A and B: Tumor cells infiltrated the tissue stroma. They were rich in cytoplasm and full of mucus, and the nucleus was squeezed on the side of the cytoplasm, resembling a signet ring (hematoxylin and eosin, 10 ×); C: Tumor cells invaded the colonic mucosa and submucosa, and the polarity of the glandular epithelial cells was still normal; D: Tumor cells invaded the entire thickness of the appendix; E: Ki-67 > 90% in the hotspot area; F: The tissue stroma of the upper rectum near the peritoneum reflex was filled with tumor cells, so an intestinal origin was considered in combination with morphology.