title: Long-term histomorphological surveillance of the pelvic ileal pouch: dysplasia develops in a subgroup of patients.
abstract: OBJECTIVE
  Little is known about the long-term morphology of the pelvic ileal pouch after restorative proctocolectomy in patients with ulcerative colitis. This study analyzed the mucosal adaptation in the pouch during a long-term follow-up.
  
  
  METHODS
  Mucosal biopsy specimens were obtained from 87 patients during a follow-up of 6.3 years (SD, 2.7; range, 3-14 years). The villous surface density, degree of inflammation, and type of mucin were determined from glycolmethacrylate-embedded sections.
  
  
  RESULTS
  Three basic patterns of mucosal adaptation were observed: regular response with normal mucosa or mild villous atrophy and no or mild inflammation (type A, 51%), transient atrophy response with temporary moderate or severe villous atrophy followed by normalization of architecture (type B, 40%), and constant atrophy response with permanent subtotal or total villous atrophy developing from the early functioning period accompanied by severe pouchitis (type C, 9%). Low-grade dysplasia occurred in 3 patients with type C response.
  
  
  CONCLUSIONS
  In a small group of patients with ulcerative colitis, the mucosa of the pelvic pouch adapts with constant severe villous atrophy accompanied by long-standing pouchitis. This group of patients should be identified and undergo regular endoscopic and histomorphological surveillance because of risk of developing neoplasia in the pouch mucosa.
authors.affiliation: Department of Pathology, Huddinge University Hospital, Karolinska Institutet, Sweden.
authors.forename: B
authors.initials: B
authors.lastname: Veress
authors.forename: F P
authors.initials: FP
authors.lastname: Reinholt
authors.forename: K
authors.initials: K
authors.lastname: Lindquist
authors.forename: R
authors.initials: R
authors.lastname: Löfberg
authors.forename: L
authors.initials: L
authors.lastname: Liljeqvist
mesh_terms: D000328:Adult; D001284:Atrophy; D003093:Colitis, Ulcerative / Q000601:surgery; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007413:Intestinal Mucosa / Q000473:pathology*; D008297:Male; D009077:Mucins / Q000032:analysis; D011183:Postoperative Complications / Q000473:pathology; D011230:Precancerous Conditions / Q000473:pathology; D016737:Proctocolectomy, Restorative
chemical_list: D009077:Mucins