Background: Small bowel adenocarcinomas (SBAs) are rare carcinomas. They are asymptomatic and usually neither endoscopy nor contrast studies are performed for screening. Case presentation: A 72-year-old Japanese male had a positive fecal occult blood test at a regular check-up in 2006. He suffered appendicitis and received an ileosigmoidostomy in 1966. A colonoscopy revealed an irregular mucosal lesion with an unclear margin at the ileum side of the anastomosis. A mucosal biopsy specimen showed adenocarcinoma histopathologically. Excision of the anastomosis was performed for this patient. The resected specimen showed a flat mucosal lesion with a slight depression at the ileum adjacent to the anastomosis. Histological examination revealed a well differentiated intramucosal adenocarcinoma (adenocarcinoma in situ). Immunohistological staining demonstrated the overexpression of p53 protein in the adenocarcinoma. Conclusion: Adenocarcinoma of the ileum at such an early stage is a very rare event. In this case, there is a possibility that the ileosigmoidostomy resulted in a back flow of colonic stool to the ileum that caused the carcinogenesis of the small intestine. © 2009 Sameshima et al; licensee BioMed Central Ltd.
Sameshima, S., Tomozawa, S., Koketsu, S., Okada, T., Miyato, H., Iijima, M., … Kaji, T. (2009). Intramucosal adenocarcinoma of the ileum originated 40 years after ileosigmoidostomy. World Journal of Surgical Oncology, 7. https://doi.org/10.1186/1477-7819-7-41