HUNNER LESION (formerly known as Hunner's ulcer)
Hunner lesion or "ulcer" is a distinctive inflammatory lesion presenting a characteristic deep rupture through the mucosa and submucosa provoked by bladder distension. Despite the name that has been commonly used, it is not an ulcer. ESSIC therefore opted to use the term Hunner lesion instead of Hunner's ulcer and this is gradually being adopted worldwide.
The detection of Hunner lesions is in general best possible at cystoscopy with hydrodistension under general, epidural or local anaesthesia by an experienced urologist trained to detect them.
Experienced urologists can detect the real majority of Hunner lesions at plain cystoscopy but for optimal treatment results, all Hunner lesions have to be identified and treated and that requires hydrodistension. (Fall M, BPS/IC World Conference, Rome 15-17 November 2012).
Definition of Hunner lesion
The following definition by Magnus Fall was accepted by ESSIC:
Hunner lesion typically presents as a circumscript, reddened mucosal area with small vessels radiating towards a central scar, with a fibrin deposit or coagulum attached to this area. This site ruptures with increasing bladder distension, with petechial oozing of blood from the lesion and the mucosal margins in a waterfall manner. A rather typical, slightly bullous edema develops post-distension with varying peripheral extension.
Interstitial cystitis (IC) with Hunner lesions is called classic IC as opposed to non-ulcer IC in which Hunner lesions are not found. Classic IC is the same as ESSIC’s BPS/IC type 3A, 3B or 3C (see http://www.essic.eu/pdf/ESSICconsensus2007.pdf) depending on whether or not biopsies were done and, if performed, the biopsy findings. It is not clear to date whether the non-ulcer and classic types represent different stages of a single disease, or whether they are different disease entities. The lack of data indicating that BPS patients without Hunner lesions progress to BPS/IC with Hunner lesions is in line with the hypothesis that they represent different diseases. Future studies, in which patients are classified according to the BPS/IC types as proposed by ESSIC, are needed to clarify this issue.
Patients with Hunner's lesions are on average 10 years older than those without, but this difference is compatible with both theories. In groups of IC patients, there is no relationship between symptoms, including pain scores and the presence of Hunner's lesions. On the other hand, bladder pain and other symptoms may improve dramatically when Hunner lesions are treated by electrocoagulation, lasercoagulation or resection. This requires that all Hunner lesions are detected and treated and this is only garanteed at cystoscopy with hydrodistension.
The bladder capacity under general anaesthesia has been found to be significantly smaller in patients with Hunner's lesions.
Luminal nitric oxide (NO) measurement in the bladder of BPS/IC patients has shown that patients with Hunner lesions have high NO levels irrespective of symptoms, while those without Hunner lesions have normal levels. Bacterial infection of the bladder must be excluded as this also causes high NO levels in the bladder. The measurement is a simple procedure and is done using an intravesical catheter with a silicon balloon. It requires a NO measuring device that is not generally available in hospitals (it costs about € 25,000).
In urology centres with the expert skills to detect Hunner lesions, Hunner lesions are detected in about 50% of the patients with BPS. The majority of BPS/IC patients with Hunner lesions, however, are probably not recognized in centres with less experience. This under-diagnosis is probably due to a combination of factors such as:
The confusion caused by the name Hunner's ulcer while it is not an ulcer: the term Hunner's ulcersuggests that it can always been seen at cystoscopy without hydrodistension
Hunner lesions can remain undetected at cystoscopy without hydrodistension
Many urologists suppose that Hunner's lesions are rare; the fact that they rarely detect them is considered to be in line with this false impression
Even when cystoscopy with hydrodistension is performed, Hunner lesions are likely to be detected mainly by experienced urologists. Biopsy may be necessary to prove that it is a Hunner lesion and/or to exclude a carcinoma in situ.
Bladder pain and other symptoms may improve dramatically when Hunner lesions are treated by electrocoagulation, lasercoagulation or resection. A promising new treatment with good results from a single centre is the cystoscopic injection of steroids (triamcinolone) into the submucosal space in the centre and periphery of lesions. (Cox M, Klutke JJ, Klutke CG. Can J Urol 2009;16:4536-40).
While Hunner lesions unfortunately tend to recur, the interval may vary between several months and more than 5 years.
Joop P van de Merwe