The testicular sphincter contains a small amount of plasma, which allows the testicle to slide within the sphincter cavity. If too much fluid is retained in the sphincter cavity, it becomes a sphingomyelomeningocele. In addition, the residual part of the peritoneal sheath in the spermatic cord that is not completely occluded can also accumulate fluid. In addition, fluid can also accumulate in the residual part of the spermatic cord where the sphincter is not completely occluded. Pediatric syringomyelia is different from that of adults. A careful anatomic study of the pathology of syringomyelia reveals that pediatric syringomyelia almost always has an unoccluded sphincter duct communicating 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. The syringomyelia of female fetuses is called NüCK duct, which descends along the round ligament, and the unclosed NüCK duct can also form syringomyelia, also called NüCK duct cyst. Clinical manifestations] Syringomyelia can be seen in all age groups of children. 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 lump does not change significantly. If the caliber of the unclosed sphincter is thicker, the lump can be seen to shrink in the morning, and the lump is obvious because the scrotum droops when it is hot, and not obvious because the scrotum contracts when it is 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, there are basically four types of syringomyelia: (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 thin syringomyelia that communicates with the abdominal cavity, but sometimes a live flap-like structure is formed and the fluid cannot flow back, resulting in (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 is injected through the sphincter, 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 the transillumination test is positive. In some cases, its tension can be reduced after repeated compression, but there is no obvious 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 toward the retroperitoneum and a cystic mass can be palpated in the lower abdomen. Treatment】 If the syringomyelia is not large and the tension is not high, surgery may not be urgent, especially for infants within 1 year of age, and there is still a chance of self-remission. If the tension is high, it may affect the blood circulation of the testis and lead to testicular atrophy, which should be treated by high sphincter ligation. The distal syringomyelia can be left untreated, and it usually regresses on its own 2 to 3 months after surgery, or the syringomyelia can be opened to release the fluid to make it more acceptable to parents. Surgical procedures previously used to treat adult syringomyelia, such as syringomyelia reversal or syringomyelia, have been abandoned for pediatric syringomyelia. Although there are other methods used to treat pediatric syringomyelia, surgical treatment is the safest and most reliable, with a very low recurrence rate. Puncture and drainage alone is difficult to achieve a cure because the unclosed syringomyelia is not treated. 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.