BASICS
DESCRIPTION
- Incomplete or improper descent of one or both testicles; also called undescended testes (1)
- Normally, descent is in the 7th to 8th month of gestation. The cryptorchid testis may be palpable or nonpalpable.
- Types of cryptorchidism
- Abdominal: located inside the internal ring
- Canalicular: located between the internal and external rings
- Ectopic: located outside the normal path of testicular descent from abdominal cavity to scrotum; may be ectopic to perineum, femoral canal, superficial inguinal pouch (most common), suprapubic area, or opposite hemiscrotum
- Retractile: fully descended testis that moves freely between the scrotum and the groin
- Iatrogenic: Previously descended testis becomes undescended secondary to scar tissue after inguinal surgery, such as an inguinal hernia repair or hydrocelectomy.
- Also may be referred to as palpable versus nonpalpable (1)
- System(s) affected: reproductive
- Synonym(s): undescended testes (UDT)
EPIDEMIOLOGY
Incidence
- Predominant age: premature newborns
- Predominant sex: male only
Prevalence
- In the United States, cryptorchidism occurs in 1-3% of full-term and 15-30% of premature newborn males (2).
- Spontaneous testicular descent occurs by age 1 to 3 months in 50-70% of full-term males with cryptorchidism.
- Descent at 6 to 9 months of age is rare (3).
ETIOLOGY AND PATHOPHYSIOLOGY
- Not fully known
- May involve alterations in
- Mechanical factors (gubernaculum, length of vas deferens and testicular vessels, groin anatomy, epididymis, cremasteric muscles, and abdominal pressure), hormonal factors (gonadotropin, testosterone, dihydrotestosterone, and m ¼llerian-inhibiting substance[MIS]), and neural factors (ilioinguinal nerve and genitofemoral nerve)
- Major regulators of testicular descent from intra-abdominal location into the bottom of the scrotum are the Leydig cell-derived hormones, testosterone, and insulin-like growth factor 3 (IGF-3).
- Mutations in the gene for IGF-3 and in the androgen receptor gene have been evaluated as possible causes of cryptorchidism as well as chromosomal alterations (1).
- Environmental factors acting as endocrine disruptors of testicular descent also may contribute to the etiology of cryptorchidism (4).
- Risk of ascent may be as high as 32% in retractile testis (5).
Genetics
Occurrence of UDT in siblings, as well as fathers, suggests a genetic etiology.
RISK FACTORS
- Family history of cryptorchidism: highest risk if brother had UDT, followed by uncle, then father (6)
- Low birth weight, prematurity, and small for gestational age are associated with a substantial increase in incidence of cryptorchidism (1). Retractile testes are at increased risk for ascent (5).
COMMONLY ASSOCIATED CONDITIONS
- Inguinal hernia/hydrocele
- Abnormalities of vas deferens and epididymis
- Intersex abnormalities
- Hypogonadotropic hypogonadism
- Germinal cell aplasia
- Prune-belly syndrome
- Meningomyelocele
- Hypospadias
- Wilms' tumor
- Prader-Willi syndrome
- Kallmann syndrome
- Cystic fibrosis
DIAGNOSIS
HISTORY
- ≥1 testicles in a site other than the scrotum
- May be an isolated defect or associated with other congenital anomalies
PHYSICAL EXAM
- Performed with warm hands, with child in sitting, standing, and squatting position
- A Valsalva maneuver and applied pressure to lower abdomen may help to identify the testes, especially a gliding testis.
- Failure to palpate a testis after repeated exams suggests an intra-abdominal or atrophic testis.
- An enlarged contralateral testis in the presence of a nonpalpable testis suggests testicular atrophy/absence.
- Testes should be palpated for quality and position at each recommended well-child visit (1)[B].
DIFFERENTIAL DIAGNOSIS
- Retractile testis (hypermobile testis) a normally descended testis that ascends into the inguinal canal because of an active cremasteric reflex (more common in males 4 to 6 years of age)
- Atrophic testis: may occur as a result of neonatal torsion
- Vanished testis may be the result of a lack of development or in utero torsion.
DIAGNOSTIC TESTS & INTERPRETATION
Initial Tests (lab, imaging)
- In phenotypic male newborn with bilateral, nonpalpable UDTs, hormone levels are helpful to determine whether the testes are present and should be evaluated for possible disorder of sexual development (1)[A].
- Luteinizing hormone (LH)
- Follicle-stimulating hormone (FSH)
- MIS
- Testosterone
- Serum electrolytes
- Karyotype
- If bilateral nonpalpable testes and presenting >3 months of age, a human chorionic gonadotropin (hCG) stimulation test to determine presence or absence of testicular tissue (hCG 2,000 IU/day for 3 days, and check testosterone before and after stimulation) as well as gonadotropins-to say testes are absent-need negative stimulation test and elevated gonadotropins (7).
- Ultrasound or other imaging modalities should not be performed in the evaluation of boys with cryptorchidism prior to referral to a specialist, as they are rarely needed in decision making (1)[B].
Follow-Up Tests & Special Considerations
- In newborns and children <6 months of age, periodic examination to determine if testis is palpable and descended prior to considering further intervention (1)
- In the absence of spontaneous testicular descent by 6 months of age (gestational age adjusted), infant should be referred to appropriate specialist and should perform surgery within 1 year (1,8)[B].
- In children with retractile testes, examination should be performed at least yearly to rule out subsequent ascent (1)[B].
- Best accuracy in predicting monarchism in boys 11 to 30 months of age with unilateral nonpalpable UDT if unilateral nonpalpable undescended testis and contralateral descended testis is 19 to 20 mm or greater in length measured by caliper (9)[B].
Diagnostic Procedures/Other
Laparoscopy is useful in a child with nonpalpable cryptorchidism to confirm testicular absence or presence accurately and to determine the feasibility of performing a standard orchidopexy.
Test Interpretation
- Higher incidence of carcinoma in UDT and alterations in spermatogenesis (10)
- Histologic changes occur by 1.5 years of age and include smaller seminiferous tubules, fewer spermatogonia, and more peritubular tissue (10,11).
TREATMENT
GENERAL MEASURES
- Rule out retractile testis.
- Appropriate health care: outpatient until surgery is performed
- Administration of chorionic gonadotropin may cause testicular descent in some boys. Reports of efficacy are inconsistent. American Urological Association (AUA) guidelines on cryptorchidism do not recommend use of hormonal therapy to induce testicular descent due to low response rate and lack of evidence for long-term efficacy (1).
MEDICATION
Medical therapy is not indicated in the United States per the AUA guidelines on cryptorchidism 2014 (1).
ISSUES FOR REFERRAL
- ≥1 testes not descended by 6 months age (1)[B]
- Bilateral nonpalpable UDTs (1)
- Newly diagnosed cryptorchidism after 6 months of age (1)[B]
SURGERY/OTHER PROCEDURES
- Reasons to consider: avoids torsion, averts trauma, decreases but does not eliminate risk of malignancy, and prevents further alterations in spermatogenesis
- In the absence of spontaneous testicular descent by 6 months of age (gestational age-adjusted), surgery should be performed within 1 year (1)[B].
- Prepubertal orchidopexy decreases risk of testicular cancer and results in 2- to 6-fold reduction in relative risk compared to postpubertal orchidopexy (1,12,13 and 14).
- Laparoscopy/abdominal exploration is performed first if testis is nonpalpable (15).
- If palpable, an inguinal approach is usually performed. If low-lying, a single incision scrotal approach can also be considered but may increase the risk of hernia (16,17).
ONGOING CARE
FOLLOW-UP RECOMMENDATIONS
- Initial follow-up within 1 month of surgery and periodically thereafter to assess testicular size/growth.
- Patients with retractile testes should be examined at least annually to monitor for secondary ascent until testis is no longer retractile (1)[B].
Patient Monitoring
- Patients should be followed after surgery to evaluate testicular growth.
- Testicular tumors occur mainly during or after puberty; thus, these children should be taught self-examination when they are older.
DIET
No restrictions
PATIENT EDUCATION
Discuss with parents about causes, available treatments and possible effects on patient's reproductive potential and also increased risk for testicular cancer and need for regular self-examination.
PROGNOSIS
- Disorder is usually corrected with medical or surgical therapy; however, there are possible lifelong consequences.
- If testicle is absent or orchiectomy is required, may consider placement of testicular prosthesis
- Early orchidopexy may decrease risk of testicular damage and risk of malignancy.
COMPLICATIONS
- Progressive failure of spermatogenesis, if left untreated; even with orchidopexy, the fertility rate is still reduced, especially with bilateral UDTs.
- Spermatogenesis is related to the duration of cryptorchidism and the location of the testis (18).
- Formerly, bilaterally cryptorchid men have a greater decrease in fertility compared with unilateral cryptorchid male and the general male population (1,19, 20, 21, 22, 23).
- Abnormalities also have been identified in the contralateral descended testis, although less severe.
REFERENCES
11 Kolon TF, Herndon CDA, Baker LA, et al. Evaluation and treatment of cryptorchidism: AUA guideline. https://www.auanet.org/education/guidelines/cryptorchidism.cfm22 Sijstermans K, Hack WW, Meijer RW, et al. The frequency of undescended testis from birth to adulthood: a review. Int J Androl. 2008;31(1):1-11.33 Berkowitz GS, Lapinski RH, Dolgin SE, et al. Prevalence and natural history of cryptorchidism. Pediatrics. 1993;92(1):44-49.44 Main KM, Skakkebaek NE, Toppari J. Cryptorchidism as part of the testicular dysgenesis syndrome: the environmental connection. Endocr Dev. 2009;14:167-173.55 Agarwal PK, Diaz M, Elder JS. Retractile testis-is it really a normal variant? J Urol. 2006;175(4):1496-1499.66 Elert A, Jahn K, Heidenreich A, et al. Population-based investigation of familial undescended testis and its association with other urogenital anomalies. J Pediatr Urol. 2005;1(6):403-407.77 Docimo SG, Silver RI, Cromie W. The undescended testicle: diagnosis and management. Am Fam Physician. 2000;62(9):2037-2044.88 Klein MD. Referral to pediatric surgical specialists. Pediatrics. 2014;133(2):350-356.99 Braga LH, Kim S, Farrokhyar F, et al. Is there an optimal contralateral cut-off size that predicts monarchism in boys with nonpalpable testes? J Pediatr Urol. 2014;10(4): 693-698.1010 Cortes D, Thorup JM, Visfeldt J. Cryptorchidism: aspects of fertility and neoplasms. A study including data of 1,335 consecutive boys who underwent testicular biopsy simultaneously with surgery for cryptorchidism. Horm Res. 2001;55(1):21-27.1111 Park KH, Lee JH, Han JJ, et al. Histological evidences suggest recommending orchiopexy within the first year of life for children with unilateral inguinal cryptorchid testis. Int J Urol. 2007;14(7):616-621.1212 Wood HM, Elder JS. Cryptorchidism and testicular cancer: separating fact from fiction. J Urol. 2009;181(2):452-461.1313 Walsh TJ, Dall'Era MA, Croughan MS, et al. Prepubertal orchiopexy for cryptorchidism may be associated with lower risk of testicular cancer. J Urol. 2007;178(4 Pt 1):1440-1446.1414 Pettersson A, Richiardi L, Nordenskjold A, et al. Age at surgery for undescended testis and risk of testicular cancer. N Engl J Med. 2007;356(18):1835-1841.1515 Patil KK, Green JS, Duffy PG. Laparoscopy for impalpable testes. BJU Int. 2005;95(5):704-708.1616 Al-Mandil M, Khoury AE, El-Hout Y, et al. Potential complications with the prescrotal approach for the palpable undescended testis? A comparison of single prescrotal incision to the traditional inguinal approach. J Urol. 2008;180(2):686-689.1717 Na SW, Kim SO, Hwang EC, et al. Single scrotal incision orchiopexy for children with palpable low-lying undescended testis: early outcome of a prospective randomized controlled study. Korean J Urol. 2011;52(9):637-641.1818 Wilkerson ML, Bartone FF, Fox L, et al. Fertility potential: a comparison of intra-abdominal and intracanalicular testes by age groups in children. Horm Res. 2001;55(1):18-20.1919 Bremholm Rasmussen T, Ingerslev HJ, H ¸strup H. Bilateral spontaneous descent of the testis after the age of 10: subsequent effects on fertility. Br J Surg. 1988;75(8):820-823.2020 Gilhooly PE, Meyers F, Lattimer JK. Fertility prospects for children with cryptorchidism. Am J Dis Child. 1984;138(10):940-943.2121 Fallon B, Kennedy TJ. Long-term follow-up of fertility in cryptorchid patients. Urology. 1985;25(5):502-504.2222 Gracia J, S ¡nchez Zalabardo J, S ¡nchez Garc a J, et al. Clinical, physical, sperm and hormonal data in 251 adults operated on for cryptorchidism in childhood. BJU Int. 2000;85(9):1100-1103.2323 Trsinar B, Muravec UR. Fertility potential after unilateral and bilateral orchidopexy for cryptorchidism. World J Urol. 2009;27(4):513-519.
ADDITIONAL READING
- Barthold JS. Undescended testis: current theories of etiology. Curr Opin Urol. 2008;18(4):395-400.
- Barthold JS, Gonz ¡lez R. The epidemiology of congenital cryptorchidism, testicular ascent and orchiopexy. J Urol. 2003;170(6 Pt 1):2396-2401.
- Cortes D. Cryptorchidism-aspects of pathogenesis, histology and treatment. Scand J Urol Nephrol Suppl. 1998;196:1-54.
- Fantasia J, Aidlen J, Lathrop W, et al. Undescended testes: a clinical and surgical review. Urol Nurs. 2015;35(3):117-126.
- Foresta C, Zuccarello D, Garolla A, et al. Role of hormones, genes, and environment in human cryptorchidism. Endocr Rev. 2008;29(5):560-580.
- Hutson JM, Balic A, Nation T, et al. Cryptorchidism. Semin Pediatr Surg. 2010;19(3):215-224.
- Kollin C, Hesser U, Ritźen EM, et al. Testicular growth from birth to two years of age, and the effect of orchidopexy at age nine months: a randomized, controlled study. Acta Paediatr. 2006;95(3):318-324.
- Lee PA. Fertility after cryptorchidism: epidemiology and other outcome studies. Urology. 2005;66(2):427-431.
CODES
ICD10
- Q53.9 Undescended testicle, unspecified
- Q53.10 Unspecified undescended testicle, unilateral
- Q53.20 Undescended testicle, unspecified, bilateral
- Q53.11 Abdominal testis, unilateral
- Q53.21 Abdominal testis, bilateral
- Q53.22 Ectopic perineal testis, bilateral
- Q53.12 Ectopic perineal testis, unilateral
ICD9
752.51 Undescended testis
SNOMED
- 204878001 Undescended testicle (disorder)
- 268228006 Undescended testes - bilateral
- 431781000124107 Bilateral intra-abdominal testes (disorder)
- 438401000124104 Palpable undescended testicle (disorder)
CLINICAL PEARLS
- If testicular descent does not occur by 6 months of age, it is unlikely to occur. Therefore, refer patients to a specialist if a testis has not descended by 6 months of age.
- Children with bilateral, nonpalpable UDTs require laboratory evaluation to determine if viable testicular tissue is present and to rule out disorder of sexual differentiation.
- Radiologic imaging has no role in the initial evaluation of cryptorchidism.
- The risk of infertility is increased with bilateral UDTs.