Adenocarcinoma of the ileal pouch mucosa: case report and literature review.

Purpose: Cancers developing near the site of the ileoanal pouch anastomosis (IPAA) have been reported, but uncommonly in the ileal pouch mucosa itself. We present a recently encountered case of ileal pouch cancer and review the literature to examine the prevalence, risk factors, and natural history of ileal pouch adenocarcinoma as well as pouch surveillance.

Methods: A chart review of the case from our institution was conducted, and a PubMed search was undertaken for articles describing adenocarcinoma arising from the ileal pouch mucosa.

Results: Twenty articles containing 26 cases were reviewed in addition to our described case. More than half were reported in the last decade. Only three cases were definitively stage 1. All seven patients who underwent regular surveillance were diagnosed with stage 1 or 2 disease. Seventeen patients had neoplasia in their original proctocolectomy specimen and six did not. The mean time from pouch creation to adenocarcinoma was 8.9 years.

Conclusions: The risk of developing ileal pouch mucosa adenocarcinoma appears low. However, increasing reports of these cancers are concerning as most patients present with advanced disease after many years. Patients with a previous history of dysplasia/cancer may be at increased risk. We believe surveillance after IPAA should include the anal transition zone and the ileal pouch mucosa. The establishment of expert consensus guidelines on pouch surveillance should be considered in the near future.