Well-differentiated neuroendocrine tumors of the lower urinary tract: biologic behavior of a rare entity

Maria Del Carmen Rodriguez Pena, Daniela C. Salles, Jonathan I. Epstein, Sofia Canete-Portillo, Aline C. Tregnago, July Ramirez, Abdelrazak Meliti, George J. Netto

Research output: Contribution to journalArticlepeer-review


The spectrum of neuroendocrine (NE) tumors in the genitourinary tract ranges from the aggressive large and small cell carcinomas to the often benign paraganglioma and well-differentiated neuroendocrine tumor (WD-NET). At least 15 pure lower urinary tract (LUT) WD-NETs have been described. Owing to the rarity of WD-NET in the LUT and the limited number of reported cases, a better definition of their biologic long-term behavior is warranted. Herein, we aim to describe 10 new cases of WD-NET arising in the LUT and expand on follow-up findings. Ten consultation cases were identified and included 6 men and 4 women who ranged from 45 to 73 years of age. Seven cases arose in the bladder with one located in the bladder neck, 1 arose in the prostatic urethra, 1 arose in the female urethra, and 1 arose in the left ureteral orifice. All lesions were confined to the lamina propria, and tumor architecture was pseudoglandular in all cases. Associated cystitis cystica et glandularis was identified in 5 cases; urothelial papilloma and florid von Brunn's nests were found in 2 additional cases. Immunohistochemical staining for synaptophysin and chromogranin was diffusely positive in 9 cases and focal in 1 case, and the Ki-67 proliferation index was 5% or less in all tumors. Follow-up ranged from 37 to 137 months (mean = 82; median = 77), and there was no evidence of residual disease or recurrence in any of the 10 patients during the follow-up period.

Original languageEnglish (US)
Pages (from-to)53-58
Number of pages6
JournalHuman pathology
StatePublished - Mar 2021


  • Carcinoid
  • Lower urinary tract
  • Neuroendocrine
  • Urinary bladder neoplasm
  • WD-NET
  • Well-differentiated

ASJC Scopus subject areas

  • Pathology and Forensic Medicine


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