Rapidly progressive synchronous multifocal gastrointestinal stenoses in bladder cancer: diagnostic challenges and...

Gastrointestinal involvement by bladder cancer is rare and typically presents as localized invasion. We report an exceptional case of primary bladder urothelial carcinoma presenting with synchronous, multifocal stenoses of the duodenum, transverse colon, descending colon, and rectum due to retroperitoneal/peritoneal dissemination with or without intramural infiltration. A 71-year-old male, initially staged as T2N0M0, experienced rapid deterioration with bilateral ureteral strictures and multiple intestinal obstructions. Despite radiologic and endoscopic evidence of circumferential narrowing, multiple mucosal biopsies were negative for malignancy. A definitive diagnosis was achieved via transrectal ultrasound-guided needle biopsy, which revealed a discohesive, "Indian-file" infiltration pattern of urothelial carcinoma cells within the muscularis propria. This case underscores the risk of profound understaging and highlights the necessity for high clinical suspicion of dissemination despite unremarkable radiological findings when an atypical discohesive growth pattern is observed.

The online version contains supplementary material available at 10.1007/s13691-026-00862-6.