Cancer in an unexpected site post pouch surgery for familial adenomatous polyposis (FAP)

INTRODUCTION: Familial Adenomatous Polyposis (FAP) is a hereditary condition characterized by multiple colorectal adenomatous polyps. FAP is the most common adenomatous polyposis syndrome. Restorative proctocolectomy is the most commonly performed surgical procedure performed for patients suffering from FAP with different options for anastomosis, namely ileorectal anastomosis (IRA) or ileal pouch anal anastomosis (IPAA). The occurrence of adenomas is a common finding during follow up and surveillance post surgery for these patients. Although there are a few cases of carcinoma that were namely at the anal transitional zone (ATZ), there are only a few cases of ileal pouch related adenocarcinoma reported. This work has been reported in line with the SCARE criteria (Agha et al., 2016) [1]. PRESENTATION OF CASE: We report a case of a 34-year-old man diagnosed with FAP who underwent proctocolectomy with IPAA, and subsequently referred to our center, who, despite appropriate measures and surveillance, developed adenocarcinoma in the ileal pouch. DISCUSSION: Restorative proctocolectomy for Familial Adenomatous Polyposis (FAP) is the mainstay of treatment. There are different surgical options, each with its own set of advantages and disadvantages. The most favored option is proctocolectomy with ileal pouch anal anastomosis (IPAA) due to because it involves resection of the rectum. Despite these interventions, adenomas and/or carcinomas have been reported on follow up post surgery. CONCLUSION: Although the risk of developing adenomas or carcinomas in the ileal pouch post proctocolectomy with IPAA is low it should not be neglected as cancer occurrence or recurrence is unpredictable even with appropriate measures.