ABSTRACT Introduction Intramural ureteral urothelial carcinoma can be difficult to diagnose, especially when presenting without mucosal abnormalities or positive cytology. In such cases, percutaneous biopsy may provide an alternative diagnostic approach. Case Presentation A 74‐year‐old man presented with acute renal failure caused by bilateral hydronephrosis. Cystoscopy showed no mucosal abnormality. Retrograde pyeloureterography revealed bilateral distal ureteral strictures, but urine cytology from ureteral catheters was negative. Imaging revealed a submucosal mass on the right dorsal bladder wall. Urothelial carcinoma was diagnosed on a computed tomography‐guided percutaneous trans‐extraperitoneal and transvesical biopsy. Neoadjuvant chemotherapy was administered and radical cystectomy performed. Pathology confirmed invasive urothelial carcinoma originating from the right intramural ureter at the ureterovesical junction with bladder muscle invasion. Conclusion This case highlights the diagnostic challenges of intramural ureteral urothelial carcinoma presenting as a submucosal bladder tumor. Computed tomography‐guided percutaneous biopsy can be a safe and effective diagnostic option in such challenging cases.
Ohtsu et al. (Sun,) studied this question.