Related Experiment Video
Updated: Jan 24, 2026

Urinary Bladder Distention Evoked Visceromotor Responses as a Model for Bladder Pain in Mice
Published on: April 27, 2014
Hunner lesion versus non-Hunner lesion interstitial cystitis/bladder pain syndrome
Kristene E Whitmore1, Magnus Fall2, Atsushi Sengiku3
1Division of Female Pelvic Medicine and Reconstructive Surgery and Urology, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA.
Background:
Global consensus on the standardization of terminology for interstitial cystitis/bladder pain syndrome is lacking and is in the formative stages. The Workshop on Hunner lesion versus non-Hunner lesion at the 2018 International Consultation on Interstitial Cystitis Japan discussed prevalence, performance and outcome of endoscopy, the role of histopathology, and markers.
Methods:
A panel of experts reviewed the literature regarding Hunner lesion vs. non-Hunner lesion interstitial cystitis/bladder pain syndrome.
Results:
The prevalence of Hunner lesion has been reported to be 5-57%. Older age and smaller anatomic bladder capacity were associated with Hunner lesions. Cystoscopy using local anesthesia is not adequate in diagnosing interstitial cystitis but is needed to rule out confusable diseases. Cystoscopy with hydrodistention and redistention of the bladder is considered standard. A Hunner lesion is visualized as a quite typical inflammatory reaction: a reddened mucosal area with small vessels radiating towards a central scar, splitting at distension, usually associated with a waterfall bleeding pattern. Biopsies from the inflamed area show inflammatory infiltrates, granulation tissue, detrusor mastocytosis, and fibrin deposits. Ablation of Hunner lesions includes transurethral resection of lesions, fulguration, laser ablation, and cortical steroid injections. Mast cell density is a somewhat controversial matter, described differently in different studies: marked increase in Hunner lesion vs. non-Hunner lesion in the majority of studies, no difference in a few. Nitric oxide appears to be a definitive marker in distinguishing Hunner lesion vs. non-Hunner lesion disease. Macrophage migration inhibitory factor is elevated in Hunner lesion patients. Increased level of urinary proinflammatory genes expression has also been found in Hunner lesion subjects.
Conclusions:
Hunner lesion patients are clinically and pathologically distinct from non-Hunner lesion bladder pain syndrome patients.
Related Concept Videos
Urinary Bladder
In males, the bladder is situated in front of the rectum, while in females, it is positioned anterior to the vagina and uterus. The bladder floor contains an inverted triangular area called the trigone, defined by the two ureteric...
Pain
Anatomy of the Genitourinary System II: Bladder and Urethra
Analgesia and Pain Management
Nephrotic Syndrome I : Introduction
Acute Coronary Syndrome I: Introduction

