[A case of prostatic cyst].

A 45-year-old man visited our hospital for further examinations because an abnormal echogram of the bladder had been noted at a medical checkup. Transrectal echography and magnetic resonance imaging (MRI) showed a cystic mass in the bladder neck. Endoscopically it was situated in the anterior aspect of the vesical neck at about the position of 12 o'clock on the dial of a clock. Transurethral resection of the cyst wall was performed under the diagnosis of prostatic cyst. Histopathologically the cyst wall was lined by flattened epithelium and this case was supposed to be classified as retention cysts. This was thought to be the 23rd case of prostatic cysts in the Japanese literature. The characteristics, diagnostic problems and treatments of prostatic cysts are discussed.