Morphologic variations of the prostatic utricle.

Anatomical variations of the prostatic utricle (PU) have rarely been reported despite an understanding of them being required for diagnosing and treating PU anomalies. This study was performed on 57 prostates to clarify the variations of this structure. Fifty prostates were dissected under a surgical microscope, five prostates were used for ultrasonography and dissection, and two others were processed for light microscopy and reconstructed into 3D models. The PU was classified into three types based on the location of its pouch. The most common type was one in which the PU projected out from between the two ejaculatory ducts. The site and shape of the utricular orifice were also diverse on the seminal colliculus, which was most commonly located on the distal three-fourths of the prostatic urethra. The results of this study clarified the variations in the anatomy of the PU and may help improve diagnosis and treatment of PU diseases.