• 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


    • 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


    • Hormonal

      • Testosterone, mullerian inhibiting substance, insulin-like 3 hormone or its receptor LGR8, epidermal growth factor and/or oestrogens. [8]

    • Environmental or maternal toxins

      • Organochlorines, environmental oestrogens, phthalate esters, smoking and pesticides

      • Maternal alcohol consumption. [3] [7] [9]

    • 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


    • 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.


    • 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


    • 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


    • 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:

      • Unilateral undescended testicle 1 in 120

      • Bilateral undescended testicles 1 in 44

      • The higher the testis is in the abdomen, the higher the risk appears. [28] [41]

    • 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]