Bladder & urothelial tract
Other nonneoplastic
Flat lesions with reactive changes
Author: Monika Roychowdhury, M.D.
Last author update: 1 June 2016
Last staff update: 1 November 2021
Copyright: 2003-2025, PathologyOutlines.com, Inc.
PubMed Search: Flat lesions with reactive changes
Table of Contents
Definition / general | Clinical features | Prognostic factors | Gross description | Microscopic (histologic) description | Positive stains | Negative stains | Differential diagnosis | Additional referencesCite this page: Roychowdhury M Flat lesions with reactive changes. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/bladderflatreactiveatypia.html. Accessed April 1st, 2025.
Definition / general
- Inflammatory atypia characterized by mild nuclear abnormalities in acutely or chronically inflamed urothelium
- Uniformly enlarged and vesicular nuclei, central prominent nucleoli
- May have frequent mitotic figures involving the lower layers of urothelium
Clinical features
- May have history of cystitis, infection, instrumentation, stones or therapy
- Not neoplastic but may coexist with dysplasia or carcinoma in situ
- Most patients present with hematuria or irritative symptoms (frequency, urgency, dysuria)
Prognostic factors
- No premalignant potential in limited clinical studies (Cancer 2000;88:625)
Gross description
- Erythematous or inflamed urothelium cystoscopically
Microscopic (histologic) description
- Urothelium is normal to slightly thickened and shows morphologic evidence of maturation
- Cells have abundant cytoplasm, nuclei may be enlarged and may have prominent nucleoli
- Lamina propria is usually inflamed with inflammation extending to the mucosa
- No nuclear hyperchromasia, no pleomorphism, no coarse chromatin pattern
Negative stains
Differential diagnosis
Additional references
