# High‐Grade Urothelial Carcinoma Arising From a Ureteral Diverticulum: A Rare Case Report

## TL;DR

A rare case of high-grade urothelial cancer in a ureteral diverticulum highlights diagnostic challenges and the need for improved strategies.

## Contribution

This case report adds to the limited literature on urothelial carcinoma arising from ureteral diverticula and emphasizes diagnostic complexities.

## Key findings

- High-grade urothelial carcinoma was diagnosed in a ureteral diverticulum after inconclusive endoscopic evaluations.
- Segmental ureteral resection with Boari flap and Psoas hitch was performed, confirming locally advanced pT3 cancer.
- The case highlights the importance of early recognition for better outcomes in rare urothelial carcinoma presentations.

## Abstract

Ureteral diverticula are rare urological anomalies characterized by outpouchings of the ureteral wall. Malignancy arising from these structures is exceptionally rare, with only a few cases reported.

We report a 57‐year‐old male with high‐grade urothelial carcinoma arising from a ureteral diverticulum in the left distal ureter. The patient experienced painless gross hematuria, and computed tomography revealed a 3 cm undetermined mass near the left distal ureter. Multiple endoscopic diagnostic procedures were inconclusive, with the final diagnosis confirmed intraoperatively. The surgery involved resection of the mass, and intraoperative frozen section analysis revealed high‐grade urothelial carcinoma. A segmental ureteral resection was performed with reconstruction using a Boari flap and Psoas hitch. Final histopathology confirmed locally advanced, high‐grade pT3 urothelial carcinoma, and adjuvant chemotherapy was recommended.

This case underscores the diagnostic and management challenges of upper tract urothelial carcinoma, especially in rare cases involving ureteral diverticula.

This report demonstrates the diagnostic difficulties and management challenges of urothelial carcinoma arising from a ureteral diverticulum. Early recognition of such untypical clinical presentations is critical to ensure timely and appropriate treatment. Understanding cases like this may lead to improved diagnostic strategies and better outcomes for patients with similar conditions.