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

BACKGROUND Diffuse invasive signet ring cell carcinoma of the colorectum is extremely rare clinically. This type of colorectal cancer has certain clinical, pathological and biological characteristics that are different from ordinary colorectal cancer. CASE SUMMARY A 31-year-old young woman was admitted to the hospital for nearly 1 wk due to recurrent symptoms of mucopurulent bloody stools and abdominal distension. Preoperative colonoscopy showed a ring-shaped intestinal wall mass 10 cm from the rectum to the anus. Three pieces of tumor tissue were removed for examination. The pathological results showed rectal mucinous adenocarcinoma. The patient underwent laparoscopic exploration under general anesthesia, and then laparoscopic total colorectal resection, ileal pouch-anal anastomosis and ileostomy were performed. The patient was switched to a FOLFOX + cetuximab regimen. After the fifth cycle, the patient was unable to tolerate further treatment due to tumor progression and multiple organ dysfunction, and died at the end of May 2020. Overall survival was 7 mo. CONCLUSION Carcinogenesis of ulcerative colitis is different from sporadic colon cancer, and the overall prognosis is extremely poor.