To the Editor:The primary seminal vesicle tumors are rare in clinical practice,[1] and the benign primary tumors are rarer. According to previous studies, the cystadenoma of seminal vesicle may possess various symptoms caused by different sizes and locations. Imaging and microscopic examinations could provide useful information in location and qualitative diagnosis. Here, we report a patient with benign cystadenoma on the right seminal vesicle.