Acquired non-neoplastic anomalies
Urinary diversion / neobladder

Author: Monika Roychowdhury, M.D. (see Authors page)

Revised: 16 March 2016, last major update July 2011

Copyright: (c) 2003-2016,, Inc.

PubMed Search: Urinary diversion[title]
Cite this page: Urinary diversion / neobladder. website. Accessed October 15th, 2018.
Definition / general
  • Portions of ileum or colon used in adults and children to treat congenital anomalies, dysfunctional bladder or post-cystectomy for malignancy
  • Options are to enlarge capacity of bladder (augmentation), channel urine into temporary artificial reservoir while a new bladder is being created or create a neobladder (new bladder after cystectomy)
    Patients who must have their bladder removed usually have three options for urine elimination:
    1. Ileal Conduit (Urostomy) – Conduit of small intestine or colon carries the urine to an opening on the abdomen
    2. Orthotopic neobladder – Neobladder made from loops of intestine to store the urine and individual can void through normal channels
    3. Continent urinary diversion – Creation of an internal pouch from loops of intestine which is connected to an opening on the abdomen through a “one way” passage
Clinical features

  • Intestinal adenocarcinoma in colonic conduits, reflux but only rare renal failure in ileal conduits, highest risk of adenocarcinoma is in augmentation cystoplasty (J Urol 1997;157:482)
  • Frequent complications but low reoperation rate in conduit urinary diversion (J Urol 2011;185:562)
  • Monitor for carcinoma with cytology (direct smears after centrifugation)
  • Note: must also monitor nonfunctionalized bladder, if present (J Urol 2006;176:620)
Case reports
Clinical images

Continent urinary diversion using ileum

Microscopic (histologic) description
  • Inflamed, atrophic and partially denuded epithelium
  • Candida in ileal conduits
Microscopic (histologic) images

Tubular adenoma with high grade dysplasia after augmentation ileocystoplasty

Differential diagnosis
  • Normal intestinal cells: aggregates are normally present in urinary diversion specimens, may resemble malignancy
Additional references