title: Vascular plexus is a differentation criterion for muscularis mucosa from muscularis propria in small biopsies and transurethral resection materials of urinary bladder?
abstract: OBJECTIVE
  Smooth muscle fibres are found within the superficial lamina propria of urinary bladder (Muscularis Mucosa). These muscle fibres of muscularis mucosa should be distinguished from the muscularis propria in cases with urothelial carcinoma, because the depth of infiltration affects prognosis and therapy modalities. The aim of the present study was to evaluate whether the presence of vascular plexus is a criterion for muscularis mucosa and to distinguish it from muscularis propria in urinary bladder biopsies and transurethral resection specimens.
  
  
  METHODS
  Hematoxylin-Eosin and Masson-Trichrome stained slides of 54 cases with urothelial carcinoma were reviewed.
  
  
  RESULTS
  In all cases (100%), thick walled vessels were observed within the lamina propria of urinary bladder. Smooth muscle layer of lamina propria was seen in 48 of 54 cases (88.8%), and these smooth muscle fibres were co-existed with thick walled vessels. In invasive urothelial carcinoma; thin smooth muscle fibres and thick walled vessels were seen within the lamina propria in 22 of 24 cases (91.7%). There were two cases (8.3%) including only vessels in small biopsies of invasive urothelial carcinoma cases. In cases with non-invasive urothelial carcinoma; muscle fibres of muscularis mucosa and vessels were found within the lamina propia in 26 of 30 cases (86.7%). In this group, muscle fibres were not detected in 4 cases (13.3%).
  
  
  CONCLUSIONS
  Muscularis mucosa can be detected histologically in urinary bladder biopsies and TUR materials. We emphasize that the presence of vascular network is a useful criterion to determine muscularis mucosa of urinary bladder, even in the absence of muscle fibres.
authors.affiliation: Department of Pathology, Faculty of Medicine, Gaziantep University, Turkey. abaydin42@yahoo.com
authors.forename: Abdullah
authors.initials: A
authors.lastname: Aydin
authors.forename: Ramazan
authors.initials: R
authors.lastname: Uçak
authors.forename: Metin
authors.initials: M
authors.lastname: Karakök
authors.forename: Muhammed Emin
authors.initials: ME
authors.lastname: Güldür
authors.forename: Nazim Emrah
authors.initials: NE
authors.lastname: Koçer
mesh_terms: D001808:Blood Vessels / Q000473:pathology*; D006801:Humans; D009130:Muscle, Smooth / Q000473:pathology*; D013194:Staining and Labeling; D001743:Urinary Bladder / Q000473:pathology; D001749:Urinary Bladder Neoplasms / Q000473:pathology* / Q000601:surgery; D019459:Urothelium / Q000473:pathology