Cryptorchidism
Definition
One or both testes are not present within the dependent portion of the scrotal sac
Risk Factors
Strong
FHx cryptorchidism
Prematurity
Low birth weight (<2.5 kg) and/or small for gestational age
Weak
Environmental exposures
Maternal alcohol use
Gestational diabetes
Prior inguinal surgery
Differential diagnosis
Epidemiology
The prevalence of cryptorchidism in newborn term infants is 2% to 9% worldwide. [2]
This decreases to 1% to 2% after the first few months of life
Congenital cryptorchidism may spontaneously resolve with the neonatal peak of testosterone by 3 months. [3]
There is controversy regarding reports of increasing incidence
Potentially due to endocrine disruption/environmental exposures
Two thirds of cases are unilateral, while the remainder are bilateral
Aetiology
Hormonal
Testosterone, mullerian inhibiting substance, insulin-like 3 hormone or its receptor LGR8, epidermal growth factor and/or oestrogens. [8]
Environmental or maternal toxins
Genetic
Up to 23% of cases have been associated with familial clustering
Mutations in insulin-like factor 3 and its receptor, LGR8, have been demonstrated in a small number of cases
Mechanical
Problems with development of the gubernaculum
Patent processus vaginalis
Impaired intra-abdominal pressure
Neuromuscular
Abnormalities of the genitofemoral nerve's calcitonin gene-related peptide or the cremasteric nucleus
Clinical features
Common
Presence of risk factors
Malpositioned or absent testis
Palpable cryptorchid testis
Non-palpable testis
Testicular asymmetry
Scrotal hypoplasia or asymmetry
Retractile testis
Uncommon
Ascending cryptorchidism
Hypospadias
Micropenis
Secondary sex characteristics/pubertal signs in prepubertal/pubertal patients
Surgical scar in the inguinal region
Pathophysiology
Incomplete migration of the testis during embryogenesis
This occurs in both androgen-dependent and androgen-independent phases. [14]
Less commonly, the underlying aetiology is either absent testis or severely atrophic testis (nubbin)
Usually thought to be secondary to malformation or the result of testicular torsion.
Investigations
Ultrasound
Testis can be identified, either within the inguinal canal or as it emerges into the superficial inguinal pouch
MRI
Testis is identified along its normal path of descent
Hormonal evaluation
With hCG stimulation test no increase in testosterone after hCG, in conjunction with elevated basal rates of gonadotropins LH and FSH, signifies that the testes are absent
Management
Retractile testicle(s)
Annual follow-up examination
Undescended testicle(s): prepubertal
No hypospadias: both testicles palpable
Orchiopexy
No hypospadias: one testicle palpable
Examination under anaesthesia + orchiopexy
Surgical exploration
No hypospadias: no testicle palpable
hCG stimulation test
Eith hypospadias
Endocrinology and/or genetic + urology referral
Undescended testicle: postpubertal
Orchiopexy ± biopsy
? Orchiectomy
Prognosis
Patient outcomes depend on multiple factors
Unilateral versus bilateral cryptorchidism
Llocation of cryptorchid testis
Age at surgical correction
Successful surgical correction has been reported as 92% to 95% for testes located beyond the external inguinal ring
Failure rates increase for testes in higher locations
Rates of testicular cancer may be somewhat higher compared to the general population
Rates of malignancy are increased nearly 6 times in patients who undergo late surgical correction or do not undergo correction of cryptorchidism compared to patients who undergo early orchiopexy. [28] [41]
Chance of later neoplasia:
Increasingly, cryptorchid patients who are infertile are using assisted reproduction and testis sperm retrieval
Often sperm can be retrieved in adult men with azoospermia with repaired uni- or bilaterally undescended testes. [42]