Urothelial neoplasms in patients 20 years or younger: A clinicopathological analysis using the World Health Organization 2004 Bladder Consensus Classification

Purpose: Urothelial neoplasms in patients younger than 20 years are rare, with conflicting data regarding clinical outcomes. Materials and 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.