Large Villous Adenomas Arising in Ileal Pouches in Familial Adenomatous Polyposis: Report of Two Cases

A restorative proctocolectomy or ileal pouch procedure is one of the main surgical options for patients with familial adenomatous polyposis. The main premise underlying the recommendation of a pouch procedure rather than an ileorectal anastomosis is that it minimizes the risk of rectal cancer. Several studies have evaluated the risk of developing pouch adenomas. There also have been reports of pouch cancers, although the long-term risk of malignancy cannot yet be quantified. Most pouch polyps reported have been small tubular adenomas with mild dysplasia. A 19-year-old female with familial adenomatous polyposis had a colectomy and ileorectal anastomosis. Progressive rectal polyposis led to a restorative proctocolectomy at aged 38 years. Four years later, a large, 3-cm × 2-cm, villous adenoma was identified in the mid pouch, which was resected endoscopically. A 32-year-old male with familial adenomatous polyposis had a restorative proctocolectomy. Ten years after surgery, pouch endoscopy revealed several large, villous adenomas arising from the pouch mucosa. These advanced polyps may present a significant risk for cancer development and require close endoscopic surveillance. These findings strengthen the recommendation for careful regular endoscopic surveillance of familial adenomatous polyposis pouches and the evaluation of management and treatment strategies for pouch adenomas.