The testicular sphincter cavity contains a small amount of plasma, which allows the testicle to have a certain range of sliding within the sphincter cavity. If too much fluid accumulates in the lumen, a sphingomyelomeningocele is formed. If the residual part of the peritoneal sphincter tube in the spermatic cord area is not completely occluded, fluid can also accumulate to form spermatic cord syringomyelia. 1. Etiology Excessive accumulation of abdominal fluid in the sphincter cavity through the unoccluded sphincter canal. 2. Symptoms A lump appears in the groin or on one or both sides of the scrotum, which grows slowly and does not cause pain. If the unclosed sphincter is thicker in caliber, the mass shrinks after lying down or sleeping. 3. Physical signs The masses are cystic with clear borders and positive transillumination test. In spermatic cord sheath effusion, the mass is located in the spermatic cord area, small in size and ovoid in shape, and the testis can be palpated under the mass. 5. Differential diagnosis (1) Inguinal hernia: The mass of inguinal hernia is not translucent, the upper pole border is unclear, and there is a feeling of impact when coughing, and it is easy to gradually retract into the abdominal cavity if there is no impaction. (2) Testicular tumor: Generally, testicular tumor becomes solid, heavier than syringomyelia, and translucent negative, but it is easily confused with cystic testicular teratoma, which can be identified by ultrasound. 6.Treatment Children with low tension syringomyelia within 1 year old have the possibility of self-healing and should be followed up and observed. Children over 1 year of age with progressive enlargement need surgery.