Julia S. Barthold, MD, FACS
BASICS
DESCRIPTION
• Cryptorchidism, or undescended testis (UDT), is failure of one or both testes to descend or remain descended in a dependent scrotal position.
• Position
– Intra-abdominal (10–20%)
– Canalicular: Within inguinal canal
– Distal to external ring, including prepubic, prescrotal/gliding, superficial inguinal pouch
– True ectopic: Perineal most common
• Subclassifications
– Congenital: Testis extrascrotal at birth
– Acquired: Testis intrascrotal at birth but found in an extrascrotal position at a subsequent time (1)
Delayed diagnosis of primary UDT
After inguinal surgery
After spontaneous postnatal descent (recurrent cryptorchidism)
– Vanishing: Blind-ending spermatic vessels and vas deferens in a boy initially diagnosed with UDT
EPIDEMIOLOGY
Incidence
• 2–4% of full-term boys
• Up to 30% of premature boys (<37 weeks gestational age)
• Up to half descend spontaneously in the first 3–6 months of life but some will reascend
• Testes of premature boys are more likely to descend and may take a year or longer
Prevalence
• 1% of boys at 1 year of age
• Up to 4% of boys undergo orchidopexy for UDT during childhood, presumably related to risk of acquired UDT
• Up to half of boys present with acquired UDT
RISK FACTORS
• Increased incidence in families (2)
– Fathers, brothers, dizygotic twins, monozygotic twins
• Low birth weight: Prematurity or SGA
• Maternal environment
• Retractile testis is a risk factor for acquired UDT in some individuals
– Unilateral > bilateral
– Risk of ascent 7–32% (3)
– Normal testes frequently retractile >6 mo up to puberty; peak at 4 yr
• Environmental exposures?—Antiandrogenic and estrogenic compounds in animal models but weak evidence for etiology in human population
Genetics
• Rare variants of INSL3 or its receptor RXFP2
• Possible association with AR or ESR1 variants
• Likely polygenic/multifactorial
PATHOPHYSIOLOGY
• Failure of complete testicular descent
• Requires normal development and function of the gubernaculum
– Arises from intermediate mesoderm 1st trimester, enlarges 2nd trimester, migrates and then regresses 3rd trimester-birth
– Requires stimulation by testicular androgens and INSL3
• Acquired UDTs are frequently located in the superficial inguinal pouch and in most cases represent primary undescended testes not clinically identifiable until a later age
ASSOCIATED CONDITIONS
• Inguinal hernia/patent processus vaginalis
– 50–90%, increased incidence in younger boys
– Rarely clinically apparent
• Epididymal anomalies
– Long-looping most common
– Detachment of caput
– Atresia rare
– Association with patent processus vaginalis
– Clinical relevance unclear
• Hypospadias
• Abdominal wall defects
– Prune Belly (triad) syndrome; omphalocele; gastroschisis
• Neurologic and musculoskelet al diseases
– Myelomeningocele, cerebral palsy
• Component of over 300 syndromes
• Abnormal Leydig cell function
– Subtle reduction in testosterone (T) and/or increased LH/T ratio
– Low incidence in nonsyndromic UDT
• Disorders of sex differentiation (DSD)
– Usually associated with abnormal urethral and/or penile development
– 46XX congenital adrenal hypoplasia (CAH) with complete penile development; very rare; bilateral non-palpable testes; urgent diagnosis in newborn due to risk of salt wasting
GENERAL PREVENTION
Unknown
DIAGNOSIS
HISTORY
• Family history of UDT
• History of inguinal hernia and/or surgery
• Maternal exposures or illness during pregnancy
• Birth history: Gestational age and birth weight
PHYSICAL EXAM
• Document testicular position at birth
• Assess scrotal development: May be hypoplastic
• Assess penile development
– Hypospadias
– Micropenis (>2 SD below mean for age)
– Ambiguous genitalia (DSD)
• Continue periodic exams to assess for spontaneous testicular descent for at least 6 mo
• Assure maintenance of scrotal position
– After spontaneous descent
– Older boys with retractile testes
Yearly exam, warm room, warm hands, relaxed child if possible
Upright cross-legged position or supine with legs abducted
• Evidence that a nonpalpable testis is absent
– Intrascrotal “nubbin” = vanishing testis
– Contralateral testicular hypertrophy (length ≥1.8 cm) (4)
DIAGNOSTIC TESTS & INTERPRETATION
Lab
• Unilateral nonpalpable testis: No testing
• Bilateral nonpalpable testes
– Rule out CAH in newborn: Karyotype; electrolytes, 17-OH progesterone
– Hormone levels: T and gonadotropin levels during postnatal surge at 1–3 mo
Low anti-Müllerian hormone (AMH)
± abnormal hCG stimulation test
Imaging
• Imaging rarely indicated (5)
– US inaccurate to determine position
– MRI/MRA more accurate but rarely used
• Potentially useful in selected cases after referral to specialist
– Obese boys with a history of palpable testes
– Failure to identify spermatic vessels after laparoscopy or abdominal exploration
Diagnostic Procedures/Surgery
• Laparoscopy
– Procedure of choice for localization and determination of status of nonpalpable testis
– Open internal ring: Distal testis likely
– Closed internal ring: No vessels: look for high abdominal testis (image); small/atretic vessels suggests distal “vanishing” testis.
– Retroperitoneal exploration to kidney may be required.
Pathologic Findings
• Testicular biopsy
– Not standard practice at orchidopexy
– Reduced spermatogonia numbers in UDT
– Reduced Ad (adult dark) spermatogonia most predictive of spermatogenic function
– Leydig cell hypoplasia and/or Sertoli cell degeneration—limited data
DIFFERENTIAL DIAGNOSIS
• Retractile testis
• Vanishing testis: Confirmation of blind-ending spermatic vessels; antenatal torsion, or vascular accident
• True agenesis
– Rare; ipsilateral failure of Wolffian duct development and Müllerian duct regression
TREATMENT
GENERAL MEASURES
• Observe for spontaneous postnatal descent
– Identify clinical hernia or torsion
– Ensure permanent, stable scrotal position by 6 mo of age, then yearly observation
– Observe longer for descent if prematurity
• Plan surgery at 6–18 mo of age if testis fails to descend to improve testicular growth (6)
• Plan surgery at diagnosis in boys with acquired UDT
MEDICATION
• Hormonal treatment not efficacious (7)
– hCG injections or LHRH nasal spray (not available in the United States)
– Slight benefit over placebo; efficacy 15–20%
– Possible adverse effects: Pigmentation, transient pubic hair, behavior changes, adverse testicular effects
– Inadequate follow-up to rule out recurrence
SURGERY/OTHER PROCEDURES
ALERT
In cases of nonpalpable testis, the surgeon must identify the spermatic vessels and confirm that they are blind-ending or associated with an intact testis.
• Surgery is treatment of choice (3)
• Approach depends on testis palpability
• Inguinal orchidopexy
– Standard approach for palpable testis
Mobilize testis via inguinal incision
High ligation of hernia sac if present
Transection of lateral retroperitoneal fascial bands to provide additional length
Medial translocation behind epigastric vessels (Prentiss maneuver) rarely needed
Higher abdominal counterincision possible if further mobilization needed
Placement of testis in sub-Dartos pouch without tension
– Success rate ∼95%
– Complications: Testicular retraction; testis, cord or nerve injury; bleeding, infection, recurrent hernia (all rare)
• Primary scrotal orchidopexy (Bianchi)
– Increasingly reported as preferred approach for testes distal to external inguinal ring
Mobilization of testis and cremasteric muscle/fascia from cord via scrotal incision
Standard fixation in subdartos pouch
Best for low testes without associated patent processus vaginalis
Repair of hernia through scrotum possible although long-term failure rate uncertain and may be higher (8)
Similar success and complication rates as compared to inguinal orchiopexy
• Laparoscopic orchidopexy
– Procedure of choice for abdominal or high canalicular testes near internal ring
Laparoscopy for testis(es) localization with two additional lower quadrant ports
Mobilization of lateral and medial peritoneal attachments to cord
Transaction of peritoneum over cord
Transfer of mobilized testis through existing or neo-internal ring and standard fixation in subdartos pouch
– Success rates 72–91%
• Open abdominal orchiopexy
– High inguinal incision; Potentially more limited access to proximal cord
– Mobilization similar to laparoscopic approach
– Success rates 77–86%
• Fowler-Stephens orchiopexy
– One- or two-stage procedure via open or laparoscopic approach
– Required for high testis and/or short spermatic vessels
– Maintain vascular supply between vas and spermatic vessels
– Transection of spermatic vessels
– Success rates 80–94%
• Orchiectomy of unilateral UDT
– Consider in high abdominal testis, short vas deferens, hypoplastic testis, adolescent/postpubertal male
• Special considerations
– Testicular biopsy in dysmorphic testis; consider in postpubertal males
– Microvascular autotransplant requires specific expertise; solitary testes in low risk patients
– Subcutaneous testis placement as last resort to maintain endocrine function
ADDITIONAL TREATMENT
Additional Therapies
Adjuvant hormonal therapy may improve germ cell number and/or maturation; long-term efficacy uncertain
ONGOING CARE
PROGNOSIS
• Fertility
– Abnormal semen analysis: Highly variable in unilateral, 20–50%, common bilateral, 75–100%
• Paternity
– Conception success essentially normal in unilateral, 90%; reduced in bilateral, 30–50%
• Malignancy: Overall relative risk 2.9–6.5
– Postpubertal presentation; risk may be decreased by prepubertal orchidopexy
– Testicular position may influence histology
– Abdominal: Seminoma more common
– Scrotal: Nonseminomatous germ cell tumor more common
COMPLICATIONS
• Testicular atrophy; increased risk for abdominal testes
• Torsion risk 10× normal
FOLLOW-UP
Patient Monitoring
• Testicular development and position during peripubertal period
• Counseling regarding potential subfertility
• Testicular self-exam
REFERENCES
1. Jensen MS, Olsen LH, Thulstrup AM, et al. Age at cryptorchidism diagnosis and orchiopexy in Denmark: A population based study of 508,964 boys born from 1995 to 2009. J Urol. 2011;186:1595.
2. Schnack TH, Zdravkovic S, Myrup C, et al. Familial aggregation of cryptorchidism—A nationwide cohort study. Am J Epidemiol. 2008;167:1453.
3. Keys C, Heloury Y. Retractile testes: A review of the current literature. J Pediatr Urol. 2012;8:2.
4. Huff DS, Snyder HM III, Hadziselimovic F, et al. An absent testis is associated with contralateral testicular hypertrophy. J Urol. 1992;148:627.
5. Tasian GE, Copp HL, Baskin LS. Diagnostic imaging in cryptorchidism: Utility, indications, and effectiveness. J Pediatr Surg. 2011;46:2406.
6. Kollin C, Stukenborg JB, Nurmio M, et al. Boys with undescended testes: Endocrine, volumetric and morphometric studies on testicular function before and after orchidopexy at nine months or three years of age. J Clin Endocrinol Metab. 2012;97:4588.
7. Penson D, Krishnaswami S, Jules A, et al. Effectiveness of hormonal and surgical therapies for cryptorchidism: A systematic review. Pediatrics. 2013;131:e1897.
8. 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;180:686.
ADDITIONAL READING
Thorup J, Cortes D. Surgical treatment and follow up on undescended testis. Pediatr Endocrinol Rev. 2009;7:38.
See Also (Topic, Algorithm, Media)
• Disorders of Sex Development (DSD)
• Groin/inguinal Mass, Male, and Female
• Groin Hernia, Pediatric
• Testis, Normal Size
• Testis, Retractile
• Testis, Tumor and Mass, Adult, General
• Undescended Testes (Cryptorchidism) Algorithm 
• Undescended Testes (Cryptorchidism) Images 
CODES
ICD9
• 752.51 Undescended testis
• 752.52 Retractile testis
• 752.89 Other specified anomalies of genital organs
ICD10
• Q53.9 Undescended testicle, unspecified
• Q53.11 Abdominal testis, unilateral
• Q55.22 Retractile testis
CLINICAL/SURGICAL PEARLS
• Spontaneous testicular descent is common in the first 6 mo of life but testes may re-ascend.
• Surgery is the standard treatment.
• Testes that appear to be scrotal at birth can be later diagnosed as cryptorchid with potentially increased risk in retractile testes.
• Routine testis exams with well-child visits are indicated.