Dysplasia in ulcerative colitis: still a challenge.

As duration of inflammatory bowel disease (IBD), in particular ulcerative colitis (UC), is a major risk factor for the development of colorectal cancer (CRC), it is rational to propose a screening colonoscopy when the risk starts to increase, i.e., after 8-10 years from the onset of disease. If low-grade dysplasia is detected, the 9-fold increased risk of developing CRC reported in the most recent meta-analysis could reasonably be viewed as justification for colectomy even if some follow-up studies have shown a lower rate of CRC. A reasonable compromise could be to continue surveillance with extensive biopsy sampling at shorter (perhaps 3-6 month) intervals. If high grade dysplasia is present, the decision is easier, because the risk of concomitant CRC may be as high as one third, assuming that the biopsies were indeed obtained from flat mucosa and not from an adenoma. Total proctocolectomy with ileal pouch anal anastomosis (IPAA) has become the most commonly performed procedure for patients with ulcerative colitis requiring elective surgery for dysplasia. Nevertheless, a recent systematic review alerted that the risk of dysplasia in anal transition zone and rectal cuff in patients undergone to restorative proctocolectomy was remarkable, mainly in patients operated on for dysplasia or colorectal cancer.