Interstitial cystitis/bladder pain syndrome (IC/BPS) is an umbrella term of chronic debilitating conditions of unknown etiology characterized by symptoms of lower urinary tract hypersensitivity such as bladder pain/discomfort, urgency, and urinary frequency. The pathological features of IC/BPS have been generally reported as non-specific chronic inflammatory changes, with mast cell infiltration as a potential key finding. However, growing evidence reveals a histological distinction between IC/BPS with Hunner lesions and IC/BPS without Hunner lesions, and also sheds doubt on the diagnostic value of the mast cell count. Specifically, IC/BPS with Hunner lesions is an inflammatory disorder characterized by pancystitis with B cell abnormalities and epithelial denudation, while IC/BPS without Hunner lesions shows minimal histological changes. The umbrella term "IC/BPS" connects totally distinct clinical entities. Pathological evaluation thus plays an important role in the precise subtyping and clinical management of IC/BPS. In addition, terminology should be developed to refer separately to IC/BPS with Hunner lesions and IC/BPS without Hunner lesions.
Histology and histopathology. 2018 Jul 17 [Epub ahead of print]
Yoshiyuki Akiyama, Yukio Homma, Daichi Maeda
Department of Urology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan. ., Department of Urology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan., Department of Cellular and Organ Pathology, Graduate School of Medicine, Akita University, Akita, Japan.