Pathophysiology: Cryptorchidism is the absence of at least one testis from the scrotum and it is the most common defect in pediatric patients (Leslie, Sajjad, & Villanueva, 2021). Cryptorchidism may occur on both testes but it typically occurs on the right side more commonly (Leslie, Sajjad, & Villanueva, 2021). 

The undescended testis might be found anywhere along the path of descent or high in the retroperitoneal abdomen to lower in the inguinal canal. In most cases, the undescended testis can be palpated in the inguinal canal, whereas in the minority of cases the testis might be palpated in the abdomen or be non-existent (Leslie, Sajjad, & Villanueva, 2021). A contributing mechanism for undescended testes in children has to do with changes in temperature. In addition, transient hormone deficiencies may lead to a lack of testicular descent in young children. This lack of descent may impair the development of the spermatogenic tissue that is developing as the child matures. Undescended testes are associated with decreased fertility, increased germ cell tumors, testicular torsion, inguinal hernias, and psychological stress (Leslie, Sajjad, & Villanueva, 2021). An undescended testis may descend on its own during the first three months of life. However, to reduce the risks an undescended testis may be brought to the scrotum using a procedure called an orchiopexy (Leslie, Sajjad, & Villanueva, 2021). 

Epidemiology: The prevalence of cryptorchidism is in premature neonates. It is estimated that 3% of full-term neonates or 30% or premature infants are born with one or two testis that are undescended at birth (Leslie, Sajjad, & Villanueva, 2021). In over 80% of neonates with cryptorchidism their testes descend naturally by the 3rd month of life (Leslie, Sajjad, & Villanueva, 2021). A normal hypothalamic-pituitary-gonadal axis is necessary for the descent of the testis in children. Nonetheless, birth weight appears to be a factor for undescended testes followed by a family history. In full term children, the cause or cryptorchidism cannot be determined making this condition an idiopathic birth defect. Some of the risk factors for cryptorchidism include infants that are small for gestational age, or smaller placental weight (Leslie, Sajjad, & Villanueva, 2021). Another risk factor includes endocrine disruptors which may interfere with normal fetal hormone balance. These include chemicals like pesticides, smoking, exposure to phthalate (DEHP), or alcohol consumption during pregnancy (Leslie, Sajjad, & Villanueva, 2021). Other factors include maternal obesity, maternal diabetes, or a family history. Physical Exam Findings: Some of the key diagnostic factors includes mispositioned or absent testis. 

The affected testis may be palpable or non-palpable, unilateral, or bilateral. During the physical exam the testis may be palpated. However, the examiner might not be able to pull the testis into the scrotum as it returns quickly to a higher position after being pulled lower into the scrotum. In other circumstances, the testis cannot be located or palpated in the scrotum, inguinal canal, or femoral or perineal regions despite a thorough examination. Other factors include testicular asymmetry. The unilateral undescended testis may be smaller than the contralateral descended testis at birth. The scrotal skin may either be well developed or poorly developed with decreased rugae and a lighter color than the contralateral scrotum in cases of unilateral undescended testis. In many cases, the testis that is located in a supra scrotal position and can be pulled down without pain into the scrotum and remain there after the traction is released. Some uncommon factors include an ascending cryptorchidism. This may present as an ascending event in patients with previously documented normal testis position in the scrotum. Differential Diagnoses and Rationale: Differential Diagnosis Rationale Disorder of sex development (DSD)​‌‍‍‍‌‍‍‍‌‍‍‍‌‌‌‌‌‌‍‍​This condition requires a urology referral to rule out DSD. Karyotyping may help distinguish between the different disorders. Female with congenital adrenal hyperplasia A severely androgenized female may present with a phallic structure and presumed bilateral undescended testis. 

Diagnostic Testing: The initial testing consists of a clinical diagnosis. This condition is usually noted on a routine physical exam. Imaging and/or laboratory evaluation are not generally recommended. Other tests to consider includes an ultrasound. “The addition of ultrasound to a clinical exam, performed also under general anesthesia and by an experienced pediatric urologist significantly increases the prediction of the correct surgical approach” (Berger et al., 2018, p. 163.e1). With the use of an ultrasound, the testis can be identified, either within the inguinal canal or as it emerges into the superficial inguinal pouch. An ultrasound is not recommended if the testis is non-palpable. In which case the current recommendation is an exam under anesthesia followed by a diagnostic laparoscopy or open surgery. Another test includes an MRI so that the testis can be identified along its normal path of descent (Berger et al., 2018). In this case, the MRI is the most effective method of identifying the testis with the help of an IV contrast agent. 

At this time there is no testing that can conclude with a 100% certainty that a testis is absent mandating surgical exploration (Berger et al., 2018). Another test that can be performed on the patient includes a hormonal evaluation with an hCG test. If there is no increase in testosterone in conjunction with an elevated rate of LH and FSH that might signify that the testes are missing (Berger et al., 2018). Medications if Applicable: There is great debate on the choice for surgical or medical approach that should be followed for this condition. HCG has long been used in the treatment of cryptorchidism. A complete descent occurs in many cases, with the highest percentages in older children and the lowest in intra-abdominal testes. In the last decades the surgical intervention has been recommended at progressively earlier ages. 

“The American Pediatric Association Guidelines do recommend the use of hormones for cases of undescended testis. Their reasoning is that a therapeutic trial of human chorionic gonadotropin (HCG) is indicated for treatment of undescended testes before surgery, because avoidance of general anesthesia is desirable for infants” (Leslie, Sajjad, & Villanueva, 2021, p. 1). The endocrinologist might consider an hCG dosing schedule like the one shown below. Dose (given twice a week for 5 weeks). Age 250 IU/dose hCG Young Infant 500 IU/dose hCG Children 6 years or younger. 1000 IU/dose hCG Children older than 6 years. Follow-up Plan: These patients should be observed with annual follow-up. 

Any development of cryptorchidism or testicular asymmetry should be treated with orchiopexy. If a retractile testis is present in the setting of a contralateral undescended testis requiring surgery, it may be reasonable to discuss proactively performing a bilateral orchiopexy procedure due to the risk associated with metachronous undescended testis. Patient outcomes depend upon multiple factors, including unilateral versus bilateral cryptorchidism, the location of the cryptorchid testis, and age of the child for surgical correction. Some advocate yearly follow-up exam with testicular self-examination once the patient reaches puberty.

 Referrals if Necessary: A referral for an endocrinologist and a surgeon might be necessary. The endocrinologist may want to treat the patient with hCG whereas the surgeon might want to perform a bilateral orchiopexy procedure if the testis fails to descend after treatment. “Orchiopexy is recommended between 6 and 18 months at the latest to protect the fertility potential and decrease the risk of malignant changes” (Shin & Jeon, 2020, p. 415). After an orchiopexy, the patient should be followed in the office at 1 month, and then 6 – 12 months later to document testis viability, posi​‌‍‍‍‌‍‍‍‌‍‍‍‌‌‌‌‌‌‍‍​tion, and size.