[Retention cyst of the prostate in a patient with urinary difficulty].

A 54-year-old man visited our clinic for dysuria. Transabdominal ultrasonography revealed a multilocular cyst at the neck of the bladder, and a cystoscopy revealed obstruction of the neck of the bladder. Dysuria improved after tamsulosin treatment was initiated, and abdominal magnetic resonance imaging (MRI) showed disappearance of the cyst. The patient had urinary difficulty again after 2 years. An MRI and cystoscopy revealed recurrence of the cyst. Tamsulosin administration was reinitiated, but his urinary difficulty did not improve. Transurethral resection of the cystic wall was performed. Histopathological examination indicated a retention cyst.