Cryptorchidism

Excerpt

Cryptorchidism is the most prevalent congenital defect involving male genitalia and is characterized by the absence of at least one testicle from the scrotum. Approximately 3% of full-term and 30% of premature male infants are born with one or both testicles undescended. Testicular descent usually occurs by the seventh month of gestation. However, around 80% of cryptorchid testes descend within the first 3 months after birth, thereby reducing the true incidence to approximately 1%. Cryptorchidism can manifest on either one or both testicles, with a higher frequency of involvement observed in the right testicle. Bilateral cryptorchidism is observed in approximately 10% of all patients with undescended testicles.

Clinicians can determine the location of undescended testicles, which are predominantly situated in the inguinal canal but are also potentially found in the abdomen or, in some cases, are entirely absent, using palpation techniques. Approximately 20% to 30% of undescended testes are nonpalpable. Spontaneous descent is unlikely if the testis has not descended by 6 months, and surgical correction should be considered. Without surgical intervention, an undescended testicle will likely descend during the initial 3 months of life. However, if undescended testes persist, it is advisable to perform an orchiopexy between the ages of 6 and 18 months to reposition the testes into the scrotum, thereby reducing risks and minimizing the potential for infertility.

The testicle can be situated at any point along the descent pathway, exhibiting characteristics such as dysgenetic, ectopic (deviating from the usual descent path), positioned high in the abdomen near the inguinal ring, hypoplastic, located in the inguinal canal, missing or absent, and often presenting unilaterally (in two-thirds of cases).

Undescended testes can result in potential long-term complications, including decreased fertility (particularly true in cases where both testicles are affected), an increased risk of testicular germ cell tumors (with an overall risk of <1%), testicular torsion, inguinal hernias, and psychological issues, if left untreated. Approximately 10% to 30% of individuals with unilateral undescended testis may experience infertility, with the risk escalating from 35% to 65% or higher for those with bilateral disease. If bilateral cryptorchid testes are left untreated, the infertility rate can exceed 90%.

Cryptorchidism is associated with male infertility in adulthood, primarily due to poor semen quality, which can be linked to compromised Sertoli cell function and its impact on Leydig cell function. Cryptorchidism, hypospadias, testicular cancer, and poor semen quality collectively constitute testicular dysgenesis syndrome. This syndrome is believed to result from harmful environmental factors that disrupt embryonal programming and gonadal development during fetal life.