Poorly differentiated neuroendocrine transformation from metastatic upper tract urothelial carcinoma

BMJ Case Reports 2026

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Authors: Failah Mohamed Lamin, Rafael Morales‐Barrera, Inés M. de Torres, Richard Mast, Xavier Maldonado, Marc Simó, Joan Carles
DOI: 10.1136/bcr-2025-266608
Cited by: 0
References: 25

Abstract

Neuroendocrine carcinomas of the genitourinary tract, though rare, are highly aggressive tumours with limited treatment options. The pathogenic mechanisms underlying the progression from urothelial carcinoma to neuroendocrine carcinoma remain poorly understood. This report presents the first documented case of metastatic urothelial carcinoma transforming into neuroendocrine carcinoma, potentially as a resistance mechanism to enfortumab-vedotin therapy, as the dynamic nature of tumour cells may contribute to resistance against evolving microenvironments and novel interventions. In this context, performing biopsies during disease progression serves as a critical tool for elucidating tumour plasticity and enhancing therapeutic strategies.

Fields of Study & Subjects

Bladder and Urothelial Cancer Treatments Urinary and Genital Oncology Studies Neuroendocrine Tumor Research Advances

Publication details

Journal / source
BMJ Case Reports
Volume
19
Issue
2
Pages
e266608–e266608
Publication date
1 February 2026
Language
EN