Cryptorchidism refers to an abnormal descent of the testicles, where the testicles fail to descend into the scrotum and instead remain positioned in the retroperitoneal space, the inguinal canal, or near the scrotal entrance. The scrotum's ability to contract and relax regulates its internal temperature to be 1.5–2°C lower than body temperature, which is essential for maintaining normal spermatogenesis. In cases of cryptorchidism, elevated temperature disrupts sperm production. Bilateral cryptorchidism results in infertility in over 50% of cases, while unilateral cryptorchidism affects fertility in more than 30% of cases. This condition also increases the likelihood of malignant transformation, particularly when the testicles are located in the retroperitoneal space, where the risk of malignancy is approximately 40 times higher than in the general population.
Testicular descent may occur spontaneously within the first year of life. If the testicle does not descend by the age of one year, a short-term course of human chorionic gonadotropin (hCG) can be administered, with intramuscular injections twice weekly at a dose of 500 U each time and a total dose of 5,000–10,000 U. If the testicle remains undescended by the age of two, orchidopexy is typically performed to reposition the testicle into the scrotum. In cases of testicular atrophy, where the affected testicle cannot be brought into the scrotum and the contralateral testicle is normal, the atrophic testicle may be surgically removed. For cases where bilateral intra-abdominal cryptorchidism prevents descent or repositioning, microsurgical techniques may be employed to perform testicular autotransplantation.