I. Overview of hematospermia Hematospermia is a common symptom in the field of urology and gynecology. In the past, due to the limitations of relevant diagnostic techniques and the lack of attention to this kind of disease, it is usually believed that hematospermia is a benign self-limiting disease, the cause of which is usually seminal vesiculitis, which can be cured by simple conservative treatments, such as anti-infection and hemostasis. However, some patients with severe and persistent hematospermia are still ineffective or recurring despite various conservative treatment measures. The prolongation of hematospermia often causes great psychological pressure, anxiety and panic to the patients, and there is also a potential risk of genitourinary tumors in clinical practice. Therefore, more in-depth examinations are needed to clarify the diagnosis of certain patients with recalcitrant hematospermia and carry out targeted treatments. With the development of modern imaging equipment and minimally invasive technology, the application of advanced imaging equipment for in-depth diagnosis of recalcitrant hematospermia and the use of transurethral endoscopic technology for effective treatment has become one of the most important technological advances in the field of men’s medicine today. The anatomical features of the seminal vesicles and prostate region The seminal vesicles are a pair of long oval sac-like structures, 3.0-5.0cm long and 1.0-1.5cm wide.They are located in the deep pelvic cavity, behind the bladder, behind and above the bottom of the prostate, the outer side of the jugular of the vas deferens, and between the base of the bladder and the rectum. The upper end of the seminal vesicle is free and enlarged as the base of the seminal vesicle glands; the lower end is tiny as the excretory duct of the seminal vesicle glands. The jugular portion of the bilateral vas deferens and the excretory ducts of the bilateral seminal vesicles converge in the plane above the prostate gland to form the bilateral ejaculatory ducts, which pass through the prostate gland and open on either side of the seminal caruncle. The length of the ejaculatory ducts is about 1.5-2 cm, with a diameter of about 1-2 mm at the proximal end, tapering towards the distal end, and the diameter of the ducts in the middle of the ejaculatory ducts is about 0.5-0.6 mm, and at the distal end is about 0.2-0.4 mm. There is a separation between the seminal vesicles and the rectum by the Dieter’s fascia (Denovilliers’ fascia). The physiologic characteristics of the ejaculatory duct diameter cause it to be highly susceptible to obstruction or blockage in pathological conditions. Inflammation around the urethra and seminal mound in the prostate department is very likely to affect the ejaculatory duct, the excretory duct of the seminal vesicles. Obstruction of the ejaculatory duct can lead to retention of seminal vesicle fluid and thus cause enlargement of the seminal vesicles, which can lead to seminal vesiculitis and hematospermia. The common causes of hematospermia There are many causes of hematospermia, and studies have shown that the most common causes of hematospermia include: medical injury, inflammation or infection of the genitourinary tract, obstruction, cysts of the genital tract, neoplastic organisms, and vascular anomalies in the urethra of the prostate. 1, medical injury Prostate puncture biopsy, cystourethroscopy, urethral dilatation, transurethral prostatectomy and other injurious operations may injure the prostate, seminal vesicles or ejaculatory ducts, resulting in transient or temporary hematospermia. Infection or inflammation is the most common cause. Seminal vesicles, prostate and urinary tract, rectum and other organs in close proximity to each other, easy to lead to infection, infection after the inflammatory process can stimulate the local ductal system mucous membrane congestion, edema and lead to bleeding. Most young patients with hematospermia have inflammation and infection as their etiology, with seminal vesiculitis and prostatitis being the most common. Most infections are nonspecific bacterial infections, but gonococcus, Mycobacterium tuberculosis, viruses, chlamydia, mycoplasma, and parasitic infections can cause hematospermia. Inflammation can also be the result of trauma, urethral foreign bodies, and chemicals. 3, obstruction or cyst The obstruction of the ejaculatory duct can cause the proximal duct of the obstruction to dilate and swell, resulting in rupture of mucosal blood vessels and bleeding. The cause of ejaculatory duct obstruction can be local inflammation, infection, or cystic compression in the region of the ejaculatory duct, such as the common prostatic microcystic cyst and mullerian duct cyst. In the seminal vesicle ejaculatory duct region there are four types of cysts: 1, prostatic cysts: located in the midline, sometimes with the urethra, ejaculatory duct traffic, more limited to the prostate within the boundary; 2, Mullerian duct cysts (Mullerian’s cysts): located in the midline, not with the ejaculatory ducts, the urethra and the vesicles, sagittal image shows tear drop, large cysts can be beyond the posterior and superior boundary of the prostate gland Ejaculatory duct cysts, also known as Wolffian’s duct cysts: they are located in the midline and do not communicate with the urethra and seminal vesicles. 4, seminal vesicle cysts: located outside and above the prostate, where the seminal vesicles are located 4, neoplasm or tumor A variety of benign tumors, such as ectopic prostate tissue in the urethra, prostatic polyps and proliferative urethritis can cause hematospermia, as well as malignant tumors of the prostate, testes and seminal vesicles. 5, vascular anomalies Varicose veins, arteriovenous malformations, and hemangiomas in the seminal vesicles, prostate urethra, and bladder neck can lead to hematuria and hematospermia.