闌尾腺癌形成膀胱瘻管是非常少見的。一位25歲男性表現反覆泌尿道感染症狀且藥物治療無效。膀胱鏡顯示一膀胱頂部腫瘤，但病理檢查顯示為慢性發炎。在進行腹腔鏡部分膀胱切除術時意外發現腫脹之闌尾大小為7.5公分乘2.0公分且沾黏於膀胱。在病理檢查顯示為闌尾腺癌後，便進行右結腸切除術，部分膀胱切除術及切除受影響之週遭結構。最終病理報告顯示為中等分化之闌尾腺癌合併膿瘍瘻管形成及膀胱慢性發炎。在此病例中膀胱出現發炎變化，但並未受到腫瘤侵犯，且唯一表現之症狀為泌尿道感染，致使術前診斷變得困難。

An adenocarcinoma of the appendix fistulating into the urinary bladder is very rare. A 25-year-old male presented with symptoms of recurrent urinary tract infection refractory to medication. Cystoscopy revealed a tumor in the bladder dome, but the pathological examination showed chronic inflammation. An engorged appendix measuring 7.5 by 2 cm and which had adhered to the urinary bladder was incidentally found during a laparotomy for a partial cystectomy. After the initial pathological examination revealed an appendiceal adenocarcinoma, a right hemicolectomy, a partial cystectomy, and resection of the involved contiguous structures were performed. The final pathology report showed a moderately differentiated adenocarcinoma of the appendix with abscess and fistula formation and chronic inflammation of the urinary bladder. This case is interesting because the urinary bladder underwent inflammatory change but was not involved with the tumor. Additionally, the only presenting symptoms being those of urinary tract infection, made a preoperative diagnosis difficult.