Clinical Features and Histologic Findings in Bladder Pain Syndrome/Interstitial Cystitis (BPS/IS): New Findings on Useful Correlations

Between 2005 and 2016, in our Department 57 consecutive patients underwent cystoscopy under anaesthesia to classify those cases suspected of BPS/IC. Patients reported long-lasting irritative bladder symptoms, including urgency, daytime frequency of seven or more episodes, nocturia, and pain in the lower abdomen, lower back, vagina or perineum during filling or after micturition. Alternative diagnoses such as urinary tract infection (UTI) were excluded. Confusable diseases were ruled out by thorough history, clinical examination, urine analysis and imaging.

By means of a detailed medical history we considered the time of symptom onset, frequency of micturitions, the presence of associated diseases. All patients were given the same questionnaire (O'Leary-Sant Interstitial Cystitis Symptom and Problem Index) (19), filled at the time of bladder biopsy.

As for the evaluation of the ICSI-ICPI scores we considered significant relevant values those ≥ 12.

All patients underwent cystoscopy with hydrodistension under general (90%) or locoregional anaesthesia. A rigid cystoscope with a Ch. 22 caliber was used, mannitol solution was used as filling fluid, and infusion height was 80 cm above the symphysis pubis. During filling the bladder was continuously inspected. At maximal capacity, distension was maintained until spontaneous filling stopped and maximum capacity was reached. At this point the bladder was drained and bladder walls and mucosa were closely examined . The bladder was then filled again at approximately half capacity, and at least three deep biopsies were taken, including detrusor muscle, from those areas with the most apparent bladder wall lesions.

All biopsies were then fixed in 4% formalin and sent to the Pathologist for examination. It was specifically asked to assess the presence of urothelial denudation, inflammatory infiltrate, counts of mast cells in the submucosa and detrusor, presence of intrafascicular fibrosis and submucosal bleeding. A cut-off of 28 mast cells / mm2 was used for the assessment of detrusor mastocytosis.