[A Case of Primary Adenocarcinoma Mucinous Subtype of the Bladder].

A 48-year-old man who presented with asymptomatic gross hematuria in July 202X had been followed up without treatment. In January 202X, he was referred to our department due to the exacerbation of his hematuria. Contrast-enhanced magnetic resonance imaging revealed bladder cancer suggested bilateral seminal vesicle and prostate invasion, and enlarged right internal and external iliac lymph nodes. The pathological diagnosis was mucinous bladder adenocarcinoma. Prostate biopsy results were negative. Upper and lower gastrointestinal examinations were unremarkable. We suspected bladder cancer cT4aN2M0. In March 202X＋1, the patient underwent robotic-assisted laparoscopic total bladder resection, pelvic lymph node dissection, and intracorporeal urinary tract modification (ileal conduit creation). The final diagnosis was primary mucinous adenocarcinoma pT4aN2M0 of the bladder. Given the heightened risk of recurrence, the patient was administered a three-month course of oxaliplatin and capecitabine (XELOX) as adjuvant postoperative chemotherapy. The patient remains free of progression at 8 months postoperatively. Adenocarcinoma of the bladder is an exceedingly rare entity, with no established chemotherapeutic protocols. Primary mucinous adenocarcinoma of the bladder is even more exceptional. Presently, only regimens similar to those for colorectal cancer or adenocarcinoma of unknown primary, including 5-fluorouracil, are considered. In our particular case, we elected to pursue XELOX therapy, aligning with the principles governing the management of colorectal cancer.