Risk of Neoplastic Change in Ileal Pouches in Familial Adenomatous Polyposis

Introduction: Neoplastic change in ileal reservoirs after proctocolectomy has been reported in patients with familial adenomatous polyposis. We aim to determine the incidence and progression of neoplastic change in the ileal pouch of familial adenomatous polyposis patients at our institution. Methods: A retrospective review of all patients who underwent proctocolectomy for familial adenomatous polyposis with construction of an ileal pouch from 1972 to 2007 was performed. Data and status at follow-up were retrieved from the Mayo Clinic Colorectal Surgery Pouch database. Results: One hundred seventeen patients were identified with a median age of 26, 52 were male. Ileal reservoirs included J-pouch (a = 104), Kock pouch (n = 9), S-pouch (n = 3), and W-pouch (n = 1). Median follow-up was 125 months. Polyps were biopsied in 33 patients: non-dysplastic polyps (n = 2), low-grade dysplasia (n = 30), and adenocarcinoma (n = 1). No patients had high-grade dysplasia. Median time to development of dysplasia was 149 months. Adenocarcinoma developed in one patient after 284 months. Risk of dysplasia at 10, 20, and 25 years was 17, 45, and 69 %, respectively. Conclusion: Though there is a high incidence of low-grade dysplasia in the ileal reservoir in familial adenomatous polyposis patients, high-grade dysplasia and cancer occur rarely. Patients with low-grade dysplasia may still necessitate regular follow-up.