Abnormal seminal vesicle morphology Seminal vesicle cyst 2024-01-25T09:04:06Z Congenital seminal vesical cysts are caused by altered development of the mesonephric (Wolffian) duct. They are often associated with abnormal development of other ipsilateral mesonephric derivatives, such as vas deferens, kidney, and ureter. A cyst (sac-like mass that may contain serous liquid or semisolid material) caused by distention of the seminal vesicle due to atresia of the ejaculatory duct.