After ultrasound and CT examination, it was found that there was an egg-sized swelling in the left lower abdominal cavity, while the doctor found no testicle in his left scrotum during the physical examination. After surgical removal of the specimen, it was confirmed that the swelling in the left abdominal cavity was a malignant transformation of the left cryptorchid (cancer)! In fact, the parents discovered the absence of testicles on the left side of the child at the age of half a year after birth, and the parents’ neglect made the poor child suffer, causing irreversible and serious consequences. What is cryptorchidism? Cryptorchidism, also known as incomplete testicular descent, is a common pediatric condition. The testicles are not inside the scrotum during the embryonic period, but are located outside the peritoneum and descend gradually into the scrotum as the embryo develops. If the testicles stay in the inguinal region or in the abdominal cavity due to various reasons, cryptorchidism is formed. A channel is formed in the inguinal region during the descent of the testis. In normal children, this channel is closed at birth, but in children with cryptorchidism, this channel remains open. Organs in the abdominal cavity such as the greater omentum and intestinal tubes can easily burst out of this channel, and in case of impaction, the burrowed organs may be necrosed! The incidence of cryptorchidism accounts for about 30% in premature infants, 4% in newborns, 0.66% at the age of 1 year, and about 0.3% in adults. The incidence decreases gradually with growth and development, but after 6 months of age, the chance of continued decline decreases significantly, or there is no longer any chance of self-healing. Cryptorchidism is mostly seen unilaterally, with a higher incidence on the right side than on the left. Pediatric cryptorchidism can lead to infertility If the testicles do not descend into the scrotum in children over 2 years old and timely treatment is not done, the spermatogenic function of the testicles will be affected later, which can lead to infertility in serious cases. This is because the testicles can only produce viable sperm in the scrotum. Usually, the testicles are very “delicate” and very sensitive to heat, and the temperature in the abdominal cavity is only 2 to 4 degrees Celsius higher than in the scrotum, it can not stand it, and it is easy to develop testicular epithelial atrophy. As a result, it either leads to the inability to produce sperm or the lack of vitality of the sperm produced,. Moreover, due to the prolonged exposure to the higher temperature in the abdominal cavity, the testicular epithelium may also become malignant and form malignant tumors. Besides, the testicles that are not in normal position are vulnerable to trauma or twisting, causing testicular damage or even atrophy!!! The psychological impact of pediatric cryptorchidism on children is also great. If cryptorchidism is not treated in time, it can produce heart damage to older children, which may be extended to adults, such as psychological introversion, isolation, low self-esteem and refusal of social interaction.