我們報告一個位於膀胱右側幤的巨大內翻乳突瘤個案。此內翻乳突瘤的直徑頗大，並以一細長的蒂蓮結於右側壁；在排尿時會以活塞機轉導致膀胱出口阻塞症狀，因此造成病患突然且反覆發生的急性尿瀦留。在施行經尿道切除膀胱腫瘤後，排尿阻塞的症狀消失，病理檢查呈現內翻乳突瘤的特性，但是亦有局部區域有非典型的細胞變化。在連續三個月的追蹤期都沒有腫瘤復發的跡象。

We report a case of a large inverted papilloma over the right lateral wall of the urinary bladder. This solid peduncular mass had a slender narrow stalk, resulting in a check-value mechanism which contributed to relapsing acute obstructive symptoms. The symptoms completely disappeared after the bladder tumor was resected transurethrally. The pathological picture showed the characteristics of an inverted papillma, however, focal areas of cytological atypia were also found. No evidence of recurrence was noted at 3 months postoperatively.