Asymptomatic chronic urachal abscess mimicking a bladder tumor.

A 72-year-old man was admitted with a lower abdominal mass, occasionally detected during a previous laparoscopy. The cystoscopy revealed a bulging mass 5 cm in diameter at the vesical dome. The computed tomography (CT) scan showed an extravescical extension in close relationship with the posterior abdominal wall. Two consecutive endoscopic biopsies and a CT-guided percutaneous biopsy were not helpful. At surgery, a mass about 10 cm in diameter was found at the vesical dome and removed "en-block". The microscopic examination showed a chronic urachal abscess. To our knowledge, this is the second case of asymptomatic urachal abcess mimicking a bladder neoplasm. The reasons of a surgical approach are discussed.