As the testis descends from the retroperitoneal space, the sphincter, which has two layers of peritoneum, also enters the scrotum through the inguinal canal. Normally, around the time of birth, the upper 2/3 of the sphincter is completely closed and the testicular sphincter forms a blind pouch that surrounds the testicle and is called the testicular sheath. A small amount of fluid accumulates in the testicular sheath, which acts as a lubricant for the testicle to move. If there is an abnormally large amount of fluid in the congenital sphincter or if the sphincter closes abnormally, causing fluid to accumulate in the sack, an effusion is formed. In addition, syringomyelia can also occur when the sheath closure is normal, due to an increase in the amount of fluid in the sheath caused by an infection of the testis or epididymis, an acquired factor such as a tumor, filariasis or trauma. Pediatric syringomyelia is different from that of adults. A careful anatomical study of the pathology of syringomyelia reveals that pediatric syringomyelia almost always has an unclosed syringomyelia duct that communicates with the abdominal cavity. The syringomyelia is usually about 2 mm in diameter, located on the anteromedial aspect of the spermatic cord, and is thin and translucent. Some syringomyelia are thicker, up to 0.5 cm in diameter, and if the syringomyelia is thick enough to allow the intestines to enter, a hernia is formed. Some sphincter ducts are as thin as a hair and can only be identified by careful dissection. In female fetuses, the syringomyelia is called the NüCK duct and descends along the round ligament. The unclosed NüCK duct can also form a syringomyelia, also known as a NüCK duct cyst. Clinical manifestations: Syringomyelia can be seen in all age groups of pediatric patients. The vast majority are boys and present as a mass in the groin or on one or both sides of the scrotum. The size of the mass does not change significantly, but if the diameter of the unclosed sphincter is thicker, the mass can be seen to shrink in the morning, and the mass is obvious because the scrotum droops in the heat, and not obvious because the scrotum contracts in the cold. Girls occasionally have syringomyelia, which is called Nuck’s cyst. Neonatal syringomyelia is quite common and may be due to continued occlusion of the syringomyelia after birth, which in some cases may gradually subside on its own. According to the location of the abnormal closure of the syringomyelia, syringomyelia is basically divided into four types: 1, spermatic cord syringomyelia: the syringomyelia near the testis is occluded, but the syringomyelia of the spermatic cord is not closed, and the fluid in the abdominal cavity flows through the inner ring into the syringomyelia of the spermatic cord, also known as spermatic cord cyst; 2, testicular syringomyelia: fluid accumulates in the syringomyelia of the testis, and there may be a fine syringomyelia with the abdominal cavity, but sometimes a live flap-like structure is formed and the fluid cannot flow back, resulting in excessive tension 3. spermatic cord and testicular syringomyelia: the fluid is located in the spermatic cord and testis, and there is a fine sphincter between the lumen and the abdominal cavity; 4. traffic syringomyelia: the entire sphincter is not closed, and the fluid in the abdominal cavity flows through the sphincter, and because the sphincter is thicker, the fluid becomes smaller when lying down or squeezing, and sometimes it is difficult to distinguish from inguinal hernia. Diagnosis A mass in the scrotum or groin with clear borders and no obvious continuity with the abdominal cavity; the mass is cystic in nature and has a positive transillumination test. In some cases, its tension can be reduced after repeated compression, but there is no significant volume reduction. If the mass is limited to the spermatic cord, it is usually small, about the size of a finger, and ovoid in shape. The testicle can be clearly retrieved under the mass, and the mass can move with pulling on the testicle. Testicular syringomyelia drapes over the bottom of the scrotum and is oval or round. If the mass is in high tension, the testicle is usually not palpable. If the mass is not in high tension, the testicle can be palpated within the cystic mass. In a few cases, the syringomyelia mass protrudes retroperitoneally and a cystic mass may be palpated in the lower abdomen. Treatment If the sphingomyelomeningocele is not large and the tension is not high, surgery may not be urgent, especially in infants under 1 year of age, as it has a chance to subside on its own. If the tension is high, it may affect the blood circulation of the testis and lead to testicular atrophy. The distal syringomyelia can be left untreated and will usually resolve on its own in 2-3 months after surgery, or the syringomyelia can be opened to release the fluid to make it more acceptable to parents. The previous procedures used to treat adult syringomyelia, such as syringomyelia reversal suture or syringomyelia, have been abandoned for pediatric syringomyelia. Laparoscopic sphincter ligation has gradually become the main treatment procedure. Although other methods are still available for the treatment of pediatric syringomyelia, surgical treatment is the most safe and reliable, with a very low recurrence rate. Puncture and drainage alone, without treatment of the unclosed syringomyelia, makes it difficult to achieve a cure. After puncture and drainage, injection of certain drugs such as uradan, hydrocortisone, urea, wine, tetracycline, and carbolic acid into the sphincter cavity is also partially effective, but these drugs may cause chemical peritonitis by flowing into the peritoneal cavity through the incompletely occluded syringomyelia, and it is not clear whether the histological reaction caused by the drugs will cause long-term damage to the developing pediatric testis.