Bladder, ureter & renal pelvis
Urothelial neoplasms - noninvasive
Dysplasia
Author: Monika Roychowdhury, M.D.
Last author update: 1 June 2016
Last staff update: 30 March 2023 (update in progress)
Copyright: 2003-2023, PathologyOutlines.com, Inc.
PubMed Search: Bladder [title] dysplasia
Table of Contents
Definition / general | Terminology | Epidemiology | Sites | Clinical features | Prognostic factors | Microscopic (histologic) description | Cytology description | Positive stains | Negative stains | Differential diagnosis | Additional referencesCite this page: Roychowdhury M. Dysplasia. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/bladderdysplasia.html. 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
Terminology
- Also known as low grade intraurothelial neoplasia (LG IUN)
Epidemiology
- Mean age 60 years, 75% male
Sites
- 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
Negative stains
Differential diagnosis
- Flat lesions with reactive atypia:
- Inflammatory atypia characterized by mild nuclear abnormalities in acutely or chronically inflamed urothelium
- Flat lesions with atypia of unknown significance:
- Atypia insufficient for diagnosis of dysplasia
- Carcinoma in situ:
- Flat lesion composed of cells in mid to upper epithelium with high cytologic grade
Additional references
