Bladder
Metaplasia
Intestinal metaplasia

Author: Rugvedita Parakh, M.D. (see Authors page)

Revised: 7 June 2016, last major update February 2013

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

PubMed Search: Intestinal metaplasia[title]
Cite this page: Intestinal metaplasia. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/bladderintestinalmetaplasia.html. Accessed December 8th, 2016.
Definition / General
Terminology
  • Also called glandular metaplasia, colonic metaplasia or goblet cell metaplasia
Epidemiology
  • Identified in 71-90% of bladders at autopsy
  • Incidence increases with age
Sites
  • Trigone is most commonly affected area
  • Also seen in ureter and renal pelvis
  • Affects the bladder mucosa, typically the lamina propria (J Urol 1968;100:462, J Urol 2006;175:1119)
  • Mostly focal but occasionally diffuse
Etiology
  • Variation of normal anatomy
  • Also due to chronic inflammation, ureteral reimplantation, neurogenic bladder, bladder exstrophy (J Urol 1981;126:822, J Urol 1987;137:764), paraplegia, stones, long term catheterization
Clinical Features
  • Incidental finding or associated with hematuria, mucosuria, dysuria, urgency or obstructive symptoms
  • May be confused cystoscopically with carcinoma, particularly if mucin extravasation is present
Prognostic Factors
  • Is it a precursor lesion for adenocarcinoma?

Yes:
  • Five large series; associated with 10-42% of reported cases of adenocarcinoma
  • If extensive, patient is at high risk for adenocarcinoma (Cancer 1987;59:2086)
  • Molecular findings support the hypothesis that intestinal metaplasia is a precursor lesion to and could be a marker in the development of adenocarcinoma of the urinary bladder (Clin Cancer Res 2007;13:6232)
  • Nuclear beta catenin positivity suggests the potential to progress to malignancy as the signaling mechanism is similar to Barrett’s esophagus (J Urol 2003;170:1892)

No:
Case Reports
Treatment
  • May regress completely if pathogenic factor is removed
Gross Description
  • Irregular rounded focal elevations of mucosa
  • Rarely polypoidal with mucinous extravasations
Micro Description
  • Replacement of urothelium by colonic mucosa (tall columnar cells)
  • Also goblet cells (single or aggregates) within Brunn’s nests, variable presence of Paneth cells
  • May coexist with cystitis cystica or cystitis glandularis
  • Mucin may be occasionally extravasated into the stroma
  • No atypia, no involvement of muscularis propria
Micro Images

Images hosted on Pathout server:

Contributed by: Rugvedita Parakh, M.D., University of Washington (USA)



Images hosted on other servers:

Cystitis glandularis intestinal type (intestinal metaplasia)

Colonic-type glands in the lamina propria


Resembles colonic mucosa

Uniform glands

Abrupt transition from urothelium

Mucin extravasation


Focal intestinal and squamous metaplasia

Cytology Description
  • Cuboidal, columnar and mucin secreting cells
  • Intestinal-type goblet cells may be seen
  • Bland cytologic features
  • Rare mitoses (Diagn Cytopathol 2008;36:181)
Positive Stains
Negative Stains
  • CK7 (usually), HEP (100%)
  • Note: in the urinary bladder, intestinal metaplasia and typical cystitis glandularis have sharply contrasting immunoprofiles despite similar morphology (Mod Pathol 2006;19:1395)
Electron Microscopy Description
    Cystitis cystica:
  • Lining cells: short microvilli on luminal surface
  • Taller cells: numerous membrane-bound electron-dense secretory granules (Br J Urol 1993;71:28)
Molecular / Cytogenetics Description
Differential Diagnosis