Two cases of heal cancer arising at the ileostomy after total proctocolectomy for familial adenomatous polyposis

We report two cases of ileal cancer arising at the ileostomy site after total proctocolectomy for familial adenomatous polyposis (FAP). Case 1: A 58-year-old man, who underwent proctocolectomy and permanent end-ileostomy for FAP when he was 31 years old, had a tumor at the ileostomy site when he was about 50 years old. The tumor increased to 5 cm. Case 2: A 65-year-old woman, who underwent proctocolectomy and permanent end-ileostomy for FAP at the age of 41, had a tumor with 3-4 cm diameter at the ileostomy site. Both patients underwent partial resection of the ileum including the tumor and ileostomy reconstruction. Final pathology revealed adenocarcinoma in both cases. Although the patho-genesis of cancer at the ileostomy site is unclear, both genetic factors and environmental factors such as physical and chemical stimuli at the ileostomy site are supposed to contribute to tumorigenesis. Cancer at the ileostomy site should be taken into consideration in the construction and care of ileostomy, and that periodic follow-up of ileostomy is necessary.