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

Abstract

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.

• Authors: Maria Del Carmen Rodriguez Pena, Daniela C Salles, Jonathan I Epstein, Sofia Canete-Portillo, Aline C Tregnago, July Ramirez, Abdelrazak Meliti, George J Netto
• Journal: Human pathology (Hum Pathol) Vol. 109 Pg. 53-58 (03 2021) ISSN: 1532-8392 [Electronic] United States
• PMID: 33301750 (Publication Type: Journal Article)
• Copyright: Copyright © 2020 Elsevier Inc. All rights reserved.

Topics

• Aged
• Female
• Humans
• Immunohistochemistry (methods)
• Male
• Middle Aged
• Neoplasm Recurrence, Local (pathology)
• Neuroendocrine Tumors (metabolism, pathology)
• Urethra (metabolism, pathology)
• Urinary Bladder (pathology)
• Urinary Bladder Neoplasms (pathology)