Seminal vesicle cyst

　　1、Etiology

　　Congenital seminal vesicle cysts can be divided into two types according to their origin: those originating from the seminal vesicle itself and those formed by abnormal development of the mesonephric duct during embryonic period. During the development of male embryos, the paramesonephric duct, mesonephric duct, and some remaining mesonephric tubules differentiate into useful structures or regress into non-useful ones. Some parts of them often form tubular or vesicular residual structures that remain in the tissues of the testicle, epididymis, or seminal vesicle. Some form cysts, while others may form cysts due to abnormal hyperplasia caused by certain factors in the long-term life after birth. Recent literature reports that the occurrence of seminal vesicle cysts is related to autosomal dominant adult polycystic kidney disease (adult polycystic kidney disease, APKD). Some people (Varney, 1954) believe that such cysts are equivalent to shortened ureters or are considered to be cystic diverticula developed from residual ureteric buds, hence some people call them 'pseudo seminal vesicle cysts'.

　　2、Pathogenesis

　　Most cysts are solitary and vary in size, with the largest ones containing thousands of milliliters of fluid. There are reports of cases with up to 5000ml, and Mr. Guojun of China reported a case with fluid reaching 2500ml. Some cases may have a narrowed or occluded seminal vesicle duct, which can lead to complications such as infection and calculus. China has reported 7 cases of concurrent calculus, with one case having as many as 157 calculus stones. The calculus is mostly composed of calcium phosphate containing fructose. Professor Wáng Shùsēn et al. analyzed a seminal vesicle calculus using an energy-dispersive spectrometer and found that all layers contained calcium oxalate, which is rare. Microscopic examination of the cyst wall shows collagenous connective tissue with a single layer of cuboidal epithelium, and inflammation can be seen. Large seminal vesicle cysts can cause obstruction of the ureter.

　　The seminal vesicle cyst often occurs with malformations of other urogenital organs, such as hypospadias, hermaphroditism, and underdeveloped kidney on the same side. There are also reports of underdeveloped kidney on the opposite side. Patients with hypospadias may have abnormal urethral openings, urinate through multiple urethral openings, and are prone to urinary tract infections. Benign malformations may cause difficulties in sexual life and are not suitable for pregnancy. Since seminal vesicle cysts can also directly compress the vas deferens, causing ejaculation disorders and triggering infertility.

　　The symptoms of this disease include hematospermia, pain in the perineum after ejaculation, hematuria, frequent urination, dysuria, and abdominal pain in larger cases, urinary obstruction, rectal examination or bimanual examination may touch the cystic mass.

　　The etiology of this disease is not yet clear, and it may be related to environmental factors, genetic factors, dietary factors, and emotional and nutritional factors during pregnancy. Therefore, it is impossible to prevent this disease directly according to the etiology. Early detection, early diagnosis, and early treatment are of great significance for indirect prevention of this disease. At the same time, it can also reduce the occurrence of complications such as infertility and sterility, and correct the abnormal reproductive organ morphology to the greatest extent.

　　B-ultrasound or CT scan examination can not only show the outline of the posterior structure of the bladder, but also distinguish the solid and cystic structures. The seminal vesicle cyst is often located on one side of the seminal vesicle in the ultrasound image, showing an echo-free area. The cyst wall is smooth and thin, with enhanced echo on the posterior wall. In CT images, it can be seen that there is a cystic thick-walled lesion in the seminal vesicle, whose density depends on the protein content in the cyst fluid (CT value 0-25Hu). The wall can be smooth or irregular. After enhancement scanning, the cyst wall can be strengthened, while the inside of the cyst is not strengthened. It may be accompanied by abnormal or absent renal morphology on one side, and seminal vesicle angiography is an important diagnostic method. Wu Hongfei et al. reported 7 cases, 6 of which were diagnosed by seminal vesicle angiography, and Hao Jinrui et al. reported 14 cases, 11 of which were diagnosed by seminal vesicle angiography. Cystoscopy examination can see the prominence of the bladder trigone and posterior wall.

　　Canabthi et al. believe that MRI is particularly useful for showing seminal vesicle lesions, and it is most suitable to show the curled and low signal enhancement of seminal vesicle cysts in T2WI. It is also seen in T1WI during enhancement.

　　1、What is good for seminal vesicle cysts

　　Eat light food, pay attention to food hygiene.

　　2、What kind of food is good for seminal vesicle cysts

　　Do not drink alcohol (including beer), do not eat spicy and刺激性 food, in order to avoid the prostatic congestion.

　　Cyst of the seminal vesicle usually does not require treatment. If the patient's symptoms are obvious, the cyst can be drained through the perineum. If there is a ureteral orifice ectopia, nephroureterectomy can be performed. If the seminal vesicle cyst is large and the symptoms are obvious, it can be surgically removed.