Pediatric cryptorchidism, or cryptorchidism, refers to the failure of the testes to descend from the lumbar retroperitoneum to the scrotum in accordance with normal developmental procedures. The incidence of cryptorchidism decreases gradually during growth and development. The incidence is about 30% in preterm infants, 4% in newborns, 0.66% at the age of 1 year, and 0.3% in adults, indicating that the descent of the testes is a gradual process and the testes can continue to descend after birth. However, after 6 months of age, the chance of continued descent decreases significantly. Symptoms: The main manifestation is flattening of the scrotum on the affected side, asymmetry of the left and right scrotum in unilateral cases, and empty and deflated scrotum in bilateral cryptorchidism. If the cryptorchid is twisted, if the cryptorchid is located at the inguinal canal or the external ring, the main manifestation is a local painful mass, no normal testicle in the scrotum of the affected side, and the gastrointestinal symptoms are mild. If the cryptorchid is located in the abdomen, the painful site after torsion is in the lower abdomen near the inner ring. The symptoms and signs of right intra-abdominal type cryptorchid torsion are quite similar to those of acute appendicitis, and the main difference is that the pressure point of intra-abdominal cryptorchid torsion is low and near the inner ring. Classification: ① intra-abdominal testis, the testis is located above the inner ring; ② intra-inguinal canal testis, the testis is located between the inner and outer rings; ③ ectopic testis testis deviates from the normal descending path from the abdominal cavity to the scrotum; ④ retracted testis, the testis can be pushed or pulled into the scrotum, and then retracted up to the groin after release. The testicles of cryptorchidism are generally small in size, soft in texture and poor in elasticity, and sometimes the testicles and epididymis are separated or there is no epididymis. If the testicles are left in the abdominal cavity and inguinal canal for a long time, the “high temperature” in the body can cause degenerative changes or even fibrosis in the varicocele of the testes, which is the spermatogenic base, and the spermatogenic cells cannot be produced, and the endocrine function is also abnormal. The endocrine function is also abnormal, so it is impossible to have children normally. Treatment Cryptorchidism is usually treated by endocrine therapy and surgery. Endocrine therapy mainly uses gonadotropins. In the case of congenital hypoplasia without testicular autogenesis, chorionic gonadotropin (HCG) or gonadotropin-releasing hormone (LHRH) can be used before the age of 3 to promote the secretion of androgenic testosterone and the development and maturation of germ cells, so that the testes can descend on their own. However, if the testis is located in the superficial inguinal fossa between the subcutaneous tissue and the tendon membrane of the external oblique abdominal muscle, treatment with the above methods is often ineffective. Surgical treatment The aim of surgical treatment is to restore the normal physiological environment of the testis and keep it at a normal temperature in the scrotum in order to maintain the patient’s fertility and minimize complications such as malignant changes. Currently, surgery is advocated to be performed at the age of 10 months to 2 years. Since the risk of malignancy in ventral cryptorchidism is four times higher than that in normal testes, ventral cryptorchidism should be treated surgically as early as possible.