title: Overdiagnosis of bladder carcinoma.
abstract: OBJECTIVE
  To describe a group of archival patients who were overdiagnosed with bladder cancer according to contemporary criteria.
  
  
  METHODS
  The study group consisted of 27 over-diagnosed patients who were identified upon review of a consecutive series of well-differentiated urothelial carcinomas (grade 1 transitional cell carcinoma) diagnosed between 1958 and 1963.
  
  
  RESULTS
  The mean patient age was 61 years (range, 34-83). Findings overdiagnosed as malignancy included urothelial papilloma (9 patients), inverted papilloma (5), exuberant von Brunn's nest proliferation (hyperplasia) (5), papillary and polypoid cystitis (4), papillary urothelial hyperplasia (2), squamous papilloma (1) and endocervicosis (1). None were treated. During a mean followup of 12.2 years, 1 patient developed carcinoma in situ 11 years after diagnosis, and 1 was diagnosed with noninvasive low-grade urothelial carcinoma 5 years after diagnosis.
  
  
  CONCLUSIONS
  The most frequent mimics of malignancy were urothelial papilloma, inverted papilloma, von Brunn nest hyperplasia and papillary polypoid cystitis. Awareness of these cancer mimics is critical to avoid overdiagnosis of bladder cancer.
authors.affiliation: Department of Pathology and Laboratory Medicine, Indiana University School of Medicine, Indianapolis, IN 46202, USA. liang_cheng@yahoo.com
authors.forename: Liang
authors.initials: L
authors.lastname: Cheng
authors.forename: David G
authors.initials: DG
authors.lastname: Bostwick
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002295:Carcinoma, Transitional Cell / Q000175:diagnosis*; D003556:Cystitis / Q000175:diagnosis*; D003951:Diagnostic Errors; D006801:Humans; D006965:Hyperplasia; D008875:Middle Aged; D010212:Papilloma / Q000175:diagnosis*; D012189:Retrospective Studies; D001749:Urinary Bladder Neoplasms / Q000175:diagnosis*