Bladder, ureter & renal pelvis

Urothelial neoplasms - noninvasive


Last author update: 1 June 2016
Last staff update: 30 March 2023 (update in progress)

Copyright: 2003-2023,, Inc.

PubMed Search: Bladder [title] dysplasia

Monika Roychowdhury, M.D.
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Cite this page: Roychowdhury M. Dysplasia. website. Accessed May 29th, 2023.
Definition / general
  • Lesions of flat, noninvasive urothelium with appreciable cytologic and architectural changes indicative of neoplasia but less than carcinoma in situ
  • Represents an early morphologic manifestation of progressive alterations between normal urothelium and carcinoma in situ
  • Also known as low grade intraurothelial neoplasia (LG IUN)
  • Mean age 60 years, 75% male
  • More common on posterior wall
Clinical features
  • Occurs de novo (primary) or in patients with concurrent or previous urothelial neoplasms (secondary)
  • 66% have irritative symptoms or hematuria; 33% have no symptoms
  • 14 - 19% develop biopsy proven progression (Cancer 2000;88:625, Am J Surg Pathol 1999;23: 443)
Prognostic factors
  • Secondary dysplasia is more common than primary and has a higher rate of progression to carcinoma than de novo dysplasia (30 - 36% versus 14 - 19%)
  • Only 3 - 10% die of bladder cancer over a 10 - 25 year period
Microscopic (histologic) description
  • Characterized by lack of maturation in basal and intermediate cell layers (not full thickness)
  • Normal urothelial thickness (may be increased or decreased) and superficial umbrella cells are present
  • Atypical cytological changes restricted to intermediate and basal cells
  • Variable mitotic activity
  • Normal lamina propria
  • Low interobserver agreement on diagnosis, even among experts
Cytology description
  • Usually normal
  • Loss of cytoplasmic clearing and nuclear polarity
  • Nuclear enlargement, nuclear membrane irregularities and nuclear hyperchromasia
Positive stains
  • CK20 (aberrant expression in deeper layers), p53 (wild type expression pattern)
Negative stains
Differential diagnosis
Additional references
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