Bladder pain syndrome: do the different morphological and cystoscopic features correlate?

For the diagnosis of bladder pain syndrome (BPS), the International Society for the Study of Bladder Pain Syndrome (ESSIC) recommends a specific diagnostic work-up using cystoscopy with hydrodistension and bladder biopsies. This study evaluates the correlation between the histological findings in bladder biopsies handled following ESSIC recommendations, as well as the importance of the histological features in BPS compared with the cystoscopic findings.

The study included 15 men and 93 women. All patients underwent cystoscopy with hydrodistension, and at least three deep biopsies including detrusor muscle were taken. For the cell count the Leder stain was used most frequently. A cut-off point of 28 mast cells/mm(2) was used for detrusor mastocytosis.

Significant correlations were found between urothelial damage and inflammatory infiltrate (p < 0.001). Detrusor mastocytosis was significantly more elevated in biopsies with normal urinary epithelium (Tukey corrected p < 0.0001) than in biopsies where the urothelium was damaged. No other correlations were found between histological findings or between histological and cystoscopic findings.

Both cystoscopy with hydrodistension and histology can be used to illustrate different pathophysiological mechanisms in patients with BPS. These results favour the use of both in the classification of BPS patients.