Comparison of cystoscopic and histological findings in patients with suspected interstitial cystitis

Purpose: Although the exact etiology of interstitial cystitis remains elusive, bladder inflammation appears to be common in many patients. The National Institutes of Health (NIH) have established diagnostic criteria for interstitial cystitis based on the presence of irritative voiding symptoms in the absence of other identifiable pathology. Cystoscopic examination with hydrodistention performed in patients under anesthesia is part of the NIH diagnostic criteria. We determine if the severity of cystoscopic findings correlated with histological evidence of inflammation in patients with suspected interstitial cystitis. Materials and Methods: A total of 69 patients who met NIH symptom criteria for interstitial cystitis and underwent cystoscopy, hydrodistention and bladder biopsy under anesthesia were reviewed. There were 2 investigators blinded to the histological data who independently reviewed operative reports. A urological pathologist blinded to the clinical data reviewed biopsies for inflammation severity. Cystoscopic and histological findings were then converted to a numeric scale. Numeric data were analyzed using the Pearson correlation coefficient. Results: Cystoscopic examination revealed no evidence of interstitial cystitis in 6 patients (9%), mild changes in 27 (39%), moderate changes in 23 (33%) and severe changes in 13 (19%). Histological examination revealed no inflammation in 21 patients (30%), mild inflammation in 28 (41%), moderate inflammation in 11 (16%) and severe inflammation in 9 (13%). Histological scores correlated poorly with total and scaled cystoscopic severity scores (r = 0.295 and 0.349, respectively). Conclusions: Severity of cystoscopic findings observed during hydrodistention with anesthesia does not appear to correlate with the degree of inflammation identified histologically in patients with suspected interstitial cystitis.