title: Histopathological characteristics of interstitial cystitis/bladder pain syndrome without Hunner lesion.
abstract: OBJECTIVE
  To assess the distinct histopathological characteristics and their clinical significance between non-Hunner-type and Hunner-type interstitial cystitis (IC)/bladder pain syndrome (BPS).
  
  
  RESULTS
  We prospectively enrolled and classified IC/BPS patients, on the basis of cystoscopic findings, as having non-Hunner-type IC and Hunner-type IC. Specimens obtained from the posterior wall in non-Hunner-type IC cases during hydrodistension or from Hunner/non-Hunner lesions in Hunner-type IC cases during transurethral resection were evaluated. Stress urinary incontinence patients with microscopic haematuria were selected as controls. Biopsy specimens were obtained from 15 non-Hunner-type IC, 15 Hunner-type IC and 5 non-IC patients. Severe and moderate fibrosis was more frequently observed in non-Hunner-type IC than in Hunner-type IC and non-IC cases. However, severe and moderate inflammation was more frequently observed in Hunner-type IC than in non-Hunner-type IC cases. The remnant urothelium was significantly decreased in Hunner-type IC cases as compared with non-Hunner-type IC and non-IC cases (P < 0.05), and non-Hunner-type IC cases showed a higher number of mast cells than Hunner-type IC and non-IC cases (P = 0.035). Accordingly, several fibrosis-promoting genes were highly expressed in bladder tissues of non-Hunner-type IC, as compared with Hunner-type IC. Patients with severe fibrosis showed significantly higher urinary frequency and smaller bladder capacity than those with moderate and mild fibrosis (all P < 0.05).
  
  
  CONCLUSIONS
  Non-Hunner-type IC is characterized by severe fibrosis and increased mast cell infiltration, whereas Hunner-type IC is characterized by severe inflammation and urothelial denudation in the entire bladder. Fibrosis in the bladder of IC/BPS patients was correlated with increased urinary frequency and decreased bladder capacity.
authors.affiliation: Department of Urology, Konkuk University Hospital, Konkuk University School of Medicine, Seoul, Korea.
authors.forename: Aram
authors.initials: A
authors.lastname: Kim
authors.affiliation: Department of Urology, Asan Medical Centre, University of Ulsan College of Medicine, Seoul, Korea.|Department of Biomedical Sciences, Asan Medical Centre, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Ju-Young
authors.initials: JY
authors.lastname: Han
authors.affiliation: Department of Urology, Asan Medical Centre, University of Ulsan College of Medicine, Seoul, Korea.|Department of Biomedical Sciences, Asan Medical Centre, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Chae-Min
authors.initials: CM
authors.lastname: Ryu
authors.affiliation: Department of Urology, Asan Medical Centre, University of Ulsan College of Medicine, Seoul, Korea.|Department of Biomedical Sciences, Asan Medical Centre, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Hwan Yeul
authors.initials: HY
authors.lastname: Yu
authors.affiliation: Department of Biomedical Sciences, Asan Medical Centre, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Seungun
authors.initials: S
authors.lastname: Lee
authors.affiliation: Department of Biomedical Sciences, Asan Medical Centre, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: YongHwan
authors.initials: Y
authors.lastname: Kim
authors.affiliation: Department of Pathology, Asan Medical Centre, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Se Un
authors.initials: SU
authors.lastname: Jeong
authors.affiliation: Department of Pathology, Asan Medical Centre, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Yong Mee
authors.identifier: http://orcid.org/0000-0001-8766-2602
authors.initials: YM
authors.lastname: Cho
authors.affiliation: Department of Biomedical Sciences, Asan Medical Centre, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Dong-Myung
authors.initials: DM
authors.lastname: Shin
authors.affiliation: Department of Urology, Asan Medical Centre, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Myung-Soo
authors.identifier: http://orcid.org/0000-0002-3293-4751
authors.initials: MS
authors.lastname: Choo
mesh_terms: D000328:Adult; D000368:Aged; D018856:Cystitis, Interstitial / Q000473:pathology*; D005260:Female; D005355:Fibrosis / Q000473:pathology; D006801:Humans; D007249:Inflammation / Q000473:pathology; D008297:Male; D008407:Mast Cells / Q000473:pathology; D008875:Middle Aged
keywords: fibrosis; hunner lesion; interstitial cystitis; mast cell