Ulcerative colitis patients with a family history of colorectal cancer should be subjected to close and careful surveillance.

We report two cases affected by neoplasia after colectomy with ileo-rectal anastomosis (IRA) with a positive family history of colon cancer. Case 1, a 41-year-old ulcerative colitis (UC) patient, underwent IRA in 1977. In 1986, biopsies showed high-grade dysplasia. She underwent resection of the rectal stump in 1986. Submucosal invasive carcinoma was found in the surgical specimen. The immunohistological study demonstrated p53 protein overexpression in the neoplastic lesion. Her family history fulfilled the Amsterdam criteria of hereditary non-polyposis colorectal cancer (HNPCC). Case 2, a 47-year-old UC patient, underwent ascending colostomy in 1975 and the following year IRA. Endoscopic mucosal resection (EMR) for a sessile adenoma was performed in 1995 and subsequently polypectomy was performed for the residual tumor. Recurrent adenoma and dysplasia in another area were detected. The immunohistological study demonstrated p53 protein overexpression only in dysplasia. Renal cancer in the right kidney was detected. Resection of the rectal stump with ileal pouch-anal anastomosis (IAA), loop ileostomy and right nephrectomy were performed in 1998. Her mother and her mother's sister had been diagnosed with colon cancer. Only in the dysplastic lesion did we detect microsatellite instability at D5S644. Both cases with neoplasia had two relatives with colorectal carcinoma. In 33 cases with UC who had been followed up, 30 cases (96.8%) without neoplasia had no family history of colorectal carcinoma. These findings suggest that UC patients with a family history of colon cancer should be put under close surveillance. It should also be emphasized that IAA is the procedure of choice for UC patients with this particular condition.