RECTAL AND DUODENAL ADENOCARCINOMAS AFTER RESTORATIVE PROCTOCOLECTOMY IN A PATIENT WITH FAMILIAL ADENOMATOUS POLYPOSIS: A CASE REPORT

Case Presentation A 48-year-old woman with a family history of intestinal neoplasms and familial adenomatous polyposis (FAP) was diagnosed with FAP at the age of 27 and underwent restorative proctocolectomy. However, 17 years after the surgery, she was diagnosed with duodenal adenocarcinoma and treated with duodenopancreatectomy. In 2022, she was diagnosed with distal rectal adenocarcinoma and opted for local excision of the tumor, followed by chemotherapy and radiotherapy (CT/RT). Exome sequencing revealed a pathogenic variant in the APC gene (c.532-1G>T), an autosomal dominant inheritance that may be associated with FAP.

Discussion FAP is an autosomal dominant high-penetrance disease characterized by the formation of numerous adenomas in the rectum and colon. Around 70-80% of cases have family history. Therefore, screening is recommended starting at age 12, and prophylactic surgical treatment is indicated from age 18. The disease is initially asymptomatic but may progress with nonspecific symptoms and tumors. Due to the colorectal and extra-intestinal manifestations of FAP, as well as the possibility of developing cancers, prophylactic surgery is recommended. This may include restorative proctocolectomy with ileal reservoir, total colectomy with ileorectal anastomosis, or total proctocolectomy with permanent ileostomy. In this case, the patient underwent restorative proctocolectomy, which involves excision of the colon and rectum. After rectal resection near the pelvic floor, 1 to 2 cm of rectal mucosa is left, followed by the formation of an ileal reservoir. During endoscopic follow-up, the patient developed adenocarcinoma in the remaining rectal stump. Despite prophylactic resection, neoplasms can still develop in rare cases, highlighting the importance of endoscopic monitoring.

Conclusion Restorative proctocolectomy is considered the gold-standard treatment for patients with more than 20 polyps in the rectum. This case is significant as it illustrates a rare occurrence in which the patient developed two malignant neoplasms despite having undergone proctocolectomy, underscoring the importance of continued endoscopic surveillance.

No conflict of interest has been declared by the author(s).

Publication History

Article published online:
25 April 2025