title: Urothelial dysplasia and other flat lesions of the urinary bladder: clinicopathologic and molecular features.
abstract: The 2004 World Health Organization classification system for urothelial neoplasia classifies flat-related preneoplastic lesions as urothelial hyperplasia (flat and papillary), reactive urothelial atypia, urothelial atypia of unknown significance, urothelial dysplasia (low-grade intraurothelial neoplasia), and urothelial carcinoma in situ (high-grade intraurothelial neoplasia). Each lesion is defined with precise nomenclature and strict morphologic criteria. In many cases, morphologic features alone suffice for diagnosis. Other cases may require a panel of immunohistochemical antibodies consisting of cytokeratin 20, p53, and CD44 for diagnosis. Recent molecular studies have provided further insight into the premalignant potential of these urothelial lesions. Herein, we present a review of flat urothelial lesions of the urinary bladder as defined by the 2004 World Health Organization classification with focus on the clinicopathologic, immunohistochemical, and molecular features.
authors.affiliation: Department of Pathology and Laboratory Medicine, Indiana University School of Medicine, Indianapolis, IN 46202, USA.
authors.forename: Kurt B
authors.initials: KB
authors.lastname: Hodges
authors.forename: Antonio
authors.initials: A
authors.lastname: Lopez-Beltran
authors.forename: Darrell D
authors.initials: DD
authors.lastname: Davidson
authors.forename: Rodolfo
authors.initials: R
authors.lastname: Montironi
authors.forename: Liang
authors.initials: L
authors.lastname: Cheng
mesh_terms: D014408:Biomarkers, Tumor; D002291:Carcinoma, Papillary / Q000473:pathology; D006801:Humans; D006965:Hyperplasia / Q000145:classification / Q000473:pathology; D011230:Precancerous Conditions / Q000145:classification / Q000473:pathology; D001743:Urinary Bladder / Q000473:pathology*; D001749:Urinary Bladder Neoplasms / Q000145:classification* / Q000473:pathology*; D019459:Urothelium / Q000473:pathology
chemical_list: D014408:Biomarkers, Tumor