Long-term histomorphological surveillance of the pelvic ileal pouch: dysplasia develops in a subgroup of patients.
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.
Veress
B
B
Department of Pathology, Huddinge University Hospital, Karolinska Institutet, Sweden.
Reinholt
F P
FP
Lindquist
K
K
Löfberg
R
R
Liljeqvist
L
L
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
D009077:Mucins