title: Urothelial neoplasms in patients 20 years or younger: a clinicopathological analysis using the world health organization 2004 bladder consensus classification.
abstract: OBJECTIVE
  Urothelial neoplasms in patients younger than 20 years are rare, with conflicting data regarding clinical outcomes.
  
  
  METHODS
  We identified 23 patients 4 to 20 years old with urothelial neoplasms, reclassified the microscopic diagnoses using the 2004 WHO/International Society of Urologic Pathology grading classification and collected data on presentation, risk factors and outcomes.
  
  
  RESULTS
  Pathological grading revealed 2 urothelial papillomas, 10 papillary urothelial neoplasms of low malignant potential (PUNLMPs), and 8 low grade and 3 high grade papillary urothelial cancers, all without invasion. Mean patient age was 13.2 years (range 4 to 20), 19 patients were male and 19 presented with gross hematuria. All lesions were solitary and measured 0.1 to 6 cm. One patient had a history of smoking and 1 had parents who smoked. Three patients (13%) had recurrences classified as either urothelial papilloma (1) or PUNLMP (2). All patients were alive with no evidence of disease after a mean followup of 4.5 years (range 6 months to 13 years).
  
  
  CONCLUSIONS
  Urothelial neoplasms in individuals younger than 20 years more commonly occur in males and are predominantly low grade with a favorable clinical outcome. Before the current classification system the 10 patients with a diagnosis of PUNLMP would have been classified as having papillary carcinoma. Thus, the diagnostic category of PUNLMP allowed 43.5% of patients in this series to avoid being labeled with "cancer" at a young age.
authors.affiliation: Department of Pathology, Johns Hopkins Hospital, Baltimore, Maryland, USA.
authors.forename: Samson W
authors.initials: SW
authors.lastname: Fine
authors.forename: Peter A
authors.initials: PA
authors.lastname: Humphrey
authors.forename: Louis P
authors.initials: LP
authors.lastname: Dehner
authors.forename: Mahul B
authors.initials: MB
authors.lastname: Amin
authors.forename: Jonathan I
authors.initials: JI
authors.lastname: Epstein
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D001707:Biopsy, Needle; D002291:Carcinoma, Papillary / Q000145:classification / Q000453:epidemiology / Q000473:pathology / Q000601:surgery; D002295:Carcinoma, Transitional Cell / Q000145:classification / Q000453:epidemiology / Q000473:pathology / Q000601:surgery; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D032921:Consensus; D015653:Cystectomy / Q000379:methods; D003558:Cystoscopy / Q000379:methods; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D009361:Neoplasm Invasiveness / Q000473:pathology*; D009367:Neoplasm Staging; D011379:Prognosis; D018570:Risk Assessment; D017678:Sex Distribution; D016019:Survival Analysis; D014481:United States / Q000453:epidemiology; D001749:Urinary Bladder Neoplasms / Q000145:classification / Q000453:epidemiology* / Q000473:pathology* / Q000601:surgery; D019459:Urothelium / Q000473:pathology*; D014944:World Health Organization