Invasive Bladder Cancer With Peritoneal Invasion and Rectal Involvement Causing Rectal, Bilateral Ureteral, and Common Bile Duct Obstruction Without a Retroperitoneal Mass: A Case Report

BC may contribute to biliary obstruction through retroperitoneal processes, underscoring the need for careful diagnostic and therapeutic assessment. Furthermore, biliary drainage enabled the initiation of systemic therapy, highlighting the importance of appropriate supportive intervention.