Calculi in the Prostatic Utricle Communicated with an Ejaculatory Duct

: We have observed a case of calculi in the prostatic utricle (PU) which suggests a different formation mechanism of calculi in the PU and reflects the variety of the PU. Several calculi were observed in the sac of the PU, which was filled with a homogenous, yellowish, jelly-like material. The material was also evident in the left ejaculatory duct. The orifice of the PU appeared as an open slit in the center of the seminal colliculus. The two openings of the ejaculatory ducts were not evident on the seminal colliculus. The apparent absence of the openings of the two ejaculatory ducts on the seminal colliculus might have been due to obstruction, possibly caused by chronic inflammation or injury to the seminal colliculus. The resulting increased pressure in the ejaculatory duct might have perforated the thin wall between the ejaculatory duct and the PU. The seminal fluid that might have entered the PU through a fistula might not have flowed easily into the prostatic urethra because the utricular orifice had a very narrow slit-shaped aperture. It appeared that the seminal fluid that accumulated in the PU had enlarged the structure, and was concentrated into several foci associated with the formation of the calculi during its long-lasting stasis.