Nonurothelial benign tumors
Villous adenoma

Author: Monika Roychowdhury, M.D.

Revised: 4 January 2018, last major update December 2014

Copyright: (c) 2003-2018,, Inc.

PubMed Search: Villous adenoma [title] bladder
Cite this page: Roychowdhury, M. Villous adenoma. website. Accessed November 18th, 2018.
Definition / general
  • Rare bladder tumor similar to colonic counterpart
  • Also called villous tumor
  • Rare
  • Typically elderly patients, more commonly found in men (Int J Urol 2008;15:551)
  • Wide age range, but usually 40-70 years
  • Arise throughout urinary tract, but most common in bladder
  • In bladder, dome and the posterior wall are the most common sites; also urachus and trigone
Clinical features
  • Hematuria, mucusuria and irritative symptoms
  • May be associated with in situ or invasive adenocarcinoma at diagnosis, less often with in situ or invasive urothelial carcinoma
Prognostic factors
  • Excellent prognosis if isolated, poorer if only in-situ adenocarcinoma and well sampled, poorest if in situ or invasive urothelial carcinoma (Hum Pathol 2002;33:236)
Case reports
Gross description
  • Resembles papillary urothelial carcinoma
  • Resembles colonic villous adenoma with pointed processes lined by pseudostratified columnar epithelium with nuclear stratification, nuclear crowding, nuclear hyperchromasia, occasional prominent nucleoli, occasional mitoses
  • Associated with cystitis glandularis and cystitis cystica
  • MUST sample entire lesion to rule out adenocarcinoma (in situ or invasive)
Microscopic (histologic) images

Images hosted on Pathout server:

Images contributed by Carlos C. Diez Freire, M.D., University of Florida

60 year old man with Zinner syndrome, including a solitary right pelvic kidney and chronic kidney disease, who presented with obstructive symptoms

AFIP images

Fig 2-52: Polypoid and villous adenoma arising at bladder dome

Images hosted on other servers:

Arising in urachal cyst

Finger-like projections

Resembles colonic adenoma

Papillary fronds covered by columnar epithelium

With coexisting adenocarcinoma

Positive stains
Negative stains
Differential diagnosis