title: Urothelial histopathology surrounding bladder carcinomas.
abstract: We studied the histological condition of the urothelium surrounding bladder carcinomas in 65 patients who underwent partial resection of the bladder. These examinations showed that urothelial abnormalities were always present, i.e. a direct transition from tumour to normal urothelium was never observed. The histological alterations were divided into 10 classes and their relative positions were determined with respect to the primary tumour site. The extension of urothelial alterations around the tumour and the severity of the alterations were related to the grade of the primary tumour. Extremely atypical abnormalities were usually found next to the tumour, whereas hardly altered urothelium was located more distant to the primary tumour site. We found three atypical types of hyperplasia more frequently than simple types of hyperplasia in the vicinity of high grade (G3) carcinomas. Total hyperplasia of basal cells was more frequent than partial hyperplasia. Furthermore, carcinoma in situ (CIS) with a persisting layer of normal superficial cells tended to be relatively far from the primary tumour site, whereas CIS without normal superficial cells was usually next to the primary site. Two models for the pathogenesis of the urothelial alterations surrounding bladder carcinomas are briefly discussed.
mesh_terms: D002278:Carcinoma in Situ / Q000145:classification / Q000473:pathology; D004848:Epithelium / Q000473:pathology; D005260:Female; D006801:Humans; D006965:Hyperplasia / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D001743:Urinary Bladder / Q000473:pathology*; D001749:Urinary Bladder Neoplasms / Q000473:pathology*