NEOPLASTIC TRANSFORMATION OF THE PELVIC POUCH MUCOSA IN PATIENTS WITHULCERATIVE-COLITIS

Background & Aims: Some patients with ulcerative colitis (UC) receivin g an ileal pelvic pouch with ileoanal anastomosis (IPAA) develop persi stent severe villous atrophy in the pouch mucosa, To investigate if mu cosal atrophy indicates a risk for subsequent neoplastic transformatio n of the ileal pouch mucosa, a follow-up study was undertaken, Methods : Seven patients with UC and an IPAA in whom persistent severe atrophy (type C) developed and 14 control patients with no or only slight atr ophy (type A) were prospectively surveyed by flexible videoendoscopy w ith multiple biopsies for assessment of possible neoplastic changes, R esults: The median time of the pouch in function was 9 years for both groups, Dysplasia was found in 5 of 7 patients in the type C group (71 %) compared with none in the type A group (P < 0.001), Four patients h ad low-grade dysplasia, and 1 patient had sequential multifocal develo pment into high-grade dysplasia, Multifocal DNA aneuploidy was found i n 2 patients, 1 with low-grade and 1 with high-grade dysplasia, Conclu sions: Patients with UC and a long-standing IPAA who develop persisten t severe mucosal atrophy ave at risk also of neoplastic transformation of the pouch mucosa.