Is There a Role for Bladder Biopsy in the Diagnosis of Non-Hunner Lesions Interstitial Cystitis?

Introduction: Bladder pain syndrome/interstitial cystitis (BPS/IC) is either Hunner lesion interstitial cystitis (HL IC) or non-Hunner lesion interstitial cystitis (N-HL IC), differing in the presence of HLs on cystoscopy. Cystoscopy is essential in diagnosing HL but are bladder biopsies useful in N-HL IC patients? Our objective was to assess bladder biopsy in patients with N-HL IC, evaluating whether the count of mast cells (MCs) and percentage of activated MCs could measure severity. Materials and Methods: This is a single-centre retrospective study. Inclusion criteria: diagnosis of BPS/IC by ESSIC definition; absence of HLs. Each patient had three bladder biopsies. Statistical analysis: χ2/Fischer's exact test; Wilcoxon signed-ranks test/Mann-Whitney U test. Statistical significance: p < 0.05. Results: We separated 48 women into Group 1 with <50% of MCs activated and Group 2 with >50%. We compared the results of the O'Leary-Sant questionnaire between the two groups and did not find any correlation between the severity of the pathology and either the MC count in the detrusor or the percentage of activated MCs in the lamina propria or detrusor. Discussion/Conclusion: These findings cast doubt on the usefulness of bladder biopsy for the evaluation of severity in N-HL IC.