Adenomatous polyps develop commonly in the ileal pouch of patients with familial adenomatous polyposis

PURPOSE: The aim of this study was to establish the prevalence of adenomato us polyps in the ileal pouch of patients with familial adenomatous polyposi s. METHOD: Forty-three patients who had an ileal pouch for familial adenoma tous polyposis were invited to have a careful endoscopic examination of the ir pouch, including dye spraying. The number of polyps was recorded, and up to ten were biopsied. In addition, four random biopsy specimens were taken from the proximal and four from the distal pouch. RESULTS: Thirty-three pa tients with a median age of 36 (range, 14-63) years who had a pouch (5 Kock and 28 pelvic) for a median of 7 (range, 1-19) years accepted the invitati on. Twenty-one patients (64 percent) had endoscopically identified polyps, the number of polyps ranging from 1 to 100 (median, 10) and varying in size from 1 to 3 mm. Fourteen patients (42 percent) had adenomatous polyps and 4 of these also had microadenomas on random biopsies. Nine of the 14 patien ts with adenomas also had lymphoid polyps. Seven patients had lymphoid poly ps only and two of these patients had a microadenoma on random biopsy. Four of 12 patients with no visible polyps had microadenomas in their random bi opsies. The presence of adenomatous polyps (Pearson's correlation; P < 0.01 ) increased with the age of the pouch. In total, 20 of 33 (60 percent) pati ents had adenomas and or microadenomas. CONCLUSION: Adenomatous polyps occu r frequently in ileal pouches. These findings are of concern, and therefore , regular surveillance seems warranted until the natural history of these a denomatous polyps is determined.