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Undescended testes

SNOMED: 99021000119109774 words•Updated 03/03/2026
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Exam Tips

  • In OSCEs, examine in a warm room with warm hands and milk from external ring to scrotum; inability to keep testis at scrotal base supports true undescended testis.
  • Do not request ultrasound in primary care for a non-palpable testis; refer appropriately instead.
  • Bilateral impalpable testes plus hypospadias/micropenis is a red-flag pattern for possible DSD and needs urgent specialist assessment.
  • Differentiate retractile from undescended testis: retractile can be manipulated into scrotum and stays transiently; true undescended cannot be maintained there.
  • Counsel that early orchidopexy improves fertility and cancer outcomes, but does not return risk fully to baseline.
  • See figure: surface anatomy of testicular descent pathway and common ectopic sites in paediatric surgery teaching diagrams.

Definition

Undescended testis (cryptorchidism) is failure of one or both testes to reach and remain in the dependent scrotum after birth, due to disrupted descent along the normal abdominal-to-inguinal-to-scrotal pathway. It includes congenital and acquired/ascending forms, and may be palpable (most cases) or non-palpable, with important implications for fertility, malignancy risk, and need for timely referral.

Pathophysiology

Testicular descent normally occurs in two gestational phases: a transabdominal phase (about 8-15 weeks) and an inguinoscrotal phase (about 25-35 weeks), with the latter strongly androgen-dependent. Cryptorchidism is thought to result from combined hormonal, anatomical, genetic, and environmental influences affecting gubernacular guidance, processus vaginalis dynamics, or androgen signalling; in some boys there is familial clustering or association with disorders of sex development. Persistent extrascrotal position exposes germ cells to higher temperature, contributing to impaired maturation, reduced spermatogenic potential, and later subfertility; risk is greatest in bilateral and higher (especially intra-abdominal) testes. Malignancy risk (especially germ-cell tumours) is increased even after orchidopexy, though earlier correction before puberty reduces this risk. See figure: normal phases of testicular descent and ectopic positions in paediatric urology/embryology atlases.

Risk Factors

  • Prematurity (<37 weeks gestation)
  • Low birth weight (<2.5 kg) or small for gestational age
  • First-degree family history (father or sibling) of undescended testis
  • Previous retractile testis (risk of secondary ascent)
  • Previous inguinal hernia surgery (risk of ascending testis)
  • Genetic syndromes (for example Prader-Willi syndrome, prune belly syndrome, congenital adrenal hyperplasia)
  • Disorders of sex development
  • Possible but weaker associations: maternal smoking, maternal alcohol use, maternal diabetes, and endocrine-disrupting chemical exposure

Clinical Features

Symptoms

  • Usually asymptomatic; often detected on newborn/infant examination
  • Parent reports an intermittently absent testis (for example palpable in warm bath, suggesting retractile testis)
  • Parent notes testis present previously but now higher/non-scrotal (suggesting ascending testis)
  • Occasional groin lump if associated inguinal hernia

Signs

  • Empty or underdeveloped hemiscrotum, unilateral or bilateral
  • Testis not felt at base of scrotum on palpation
  • Palpable inguinal testis that cannot be maintained in scrotum suggests true undescended testis
  • Testis can be manipulated into scrotum then later retracts suggests retractile testis
  • Non-palpable testis in scrotum/inguinal canal raises intra-abdominal, atrophic, or absent testis
  • Features suggesting DSD (for example bilateral impalpable testes, hypospadias, micropenis, bifid scrotum) require urgent specialist assessment

Investigations

Clinical examination in warm environment (supine, and if needed sitting/squatting):Defines palpable versus non-palpable testis; assesses whether testis can be brought to and remain at scrotal base
Primary care imaging (ultrasound):Not routinely recommended for non-palpable testis because it does not reliably alter management
Specialist diagnostic laparoscopy (for persistent non-palpable testis):Localizes intra-abdominal testis or confirms absent/vanishing testis
Endocrine/genetic work-up when bilateral impalpable testes or suspected DSD:May identify chromosomal, hormonal, or receptor-level disorders affecting sexual development

Management

Lifestyle Modifications

  • Explain condition and natural history to parents, including that some testes descend spontaneously in early infancy (especially in preterm infants corrected for gestational age)
  • Ensure scheduled re-examination in infancy and reinforce attendance for screening points (newborn and 6-8 weeks; reassess around 4-5 months if previously undescended)
  • Provide safety-net advice: seek urgent review for acute groin/scrotal pain or swelling (possible torsion/hernia)

Pharmacological Treatment

No disease-modifying drug therapy for cryptorchidism

  • None routinely recommended in UK primary care for inducing descent

Hormonal treatment (for example hCG or GnRH analogues) is not routine first-line management in UK practice; definitive treatment is surgical when descent does not occur.

Peri-operative analgesia (post-orchidopexy, if required)

  • Paracetamol oral 15 mg/kg every 4-6 hours (max 4 doses in 24 hours)
  • Ibuprofen oral 5-10 mg/kg three to four times daily (usual max 30 mg/kg/day)

Use age-appropriate paediatric formulations and local BNFC protocols. Avoid ibuprofen in dehydration, active GI bleeding, severe renal impairment, or NSAID hypersensitivity.

Surgical / Interventional

  • Urgent same-day referral (within 24 hours) to paediatrics if bilateral impalpable testes at birth or suspected disorder of sex development
  • If testes remain non-scrotal by about 4-5 months, refer to paediatric surgery/urology so orchidopexy can be planned in the first year of life (ideally 6-12 months, and generally before 18 months)
  • Inguinal orchidopexy for palpable undescended testis
  • Laparoscopic orchidopexy or staged approach for intra-abdominal testis
  • Orchidectomy may be considered for severely atrophic testis or selected post-pubertal presentations after specialist review

Complications

  • Reduced fertility/subfertility risk (higher in bilateral disease)
  • Increased lifetime risk of testicular germ-cell malignancy (risk reduced but not abolished by early orchidopexy)
  • Testicular torsion
  • Associated inguinal hernia
  • Psychological/body-image impact in later childhood and adolescence

Prognosis

Outcomes are best with early recognition and timely orchidopexy, which improves fertility potential and lowers (but does not eliminate) later cancer risk. Unilateral cases generally have near-normal paternity rates, whereas bilateral undescended testes carry substantially greater reproductive risk. Long-term testicular awareness and self-examination education in adolescence/adulthood remain important because baseline malignancy risk stays above population level.

Sources & References

✅NICE Guidelines(1)

📖Textbook References(20)

  • David Randall PhD MRCP (Editor), John Booth PhD MRCP (Editor), K - Kumar and Clark's Clinical Medicine (2025, American Elsevier Publishing Co.) - libgen.li.pdf(pp. 1844)[context]
  • David Randall PhD MRCP (Editor), John Booth PhD MRCP (Editor), K - Kumar and Clark's Clinical Medicine (2025, American Elsevier Publishing Co.) - libgen.li.pdf(pp. 1724, 1725)[context]
  • David Randall PhD MRCP (Editor), John Booth PhD MRCP (Editor), K - Kumar and Clark's Clinical Medicine (2025, American Elsevier Publishing Co.) - libgen.li.pdf(pp. 1725)[context]
  • David Randall PhD MRCP (Editor), John Booth PhD MRCP (Editor), K - Kumar and Clark's Clinical Medicine (2025, American Elsevier Publishing Co.) - libgen.li.pdf(pp. 1845)[context]
  • David Randall PhD MRCP (Editor), John Booth PhD MRCP (Editor), K - Kumar and Clark's Clinical Medicine (2025, American Elsevier Publishing Co.) - libgen.li.pdf(pp. 1220)[context]
  • David Randall PhD MRCP (Editor), John Booth PhD MRCP (Editor), K - Kumar and Clark's Clinical Medicine (2025, American Elsevier Publishing Co.) - libgen.li.pdf(pp. 1725)[context]
  • Guyton and Hall Textbook of Medical Physiology (John E. Hall, Michael E. Hall) (Z-Library).pdf(pp. 1003)[context]
  • [Oxford Medical Handbooks] Ian Wilkinson, Tim Raine, Kate Wiles, Anna Goodhart, Catriona Ha - Oxford Handbook of Clinical Medicine (2017, Oxford University Press) - libgen.li.pdf(pp. 665)[context]
  • [Oxford Medical Handbooks] Ian Wilkinson, Tim Raine, Kate Wiles, Anna Goodhart, Catriona Ha - Oxford Handbook of Clinical Medicine (2017, Oxford University Press) - libgen.li.pdf(pp. 905)[context]
  • [Oxford Medical Handbooks] Ian Wilkinson, Tim Raine, Kate Wiles, Anna Goodhart, Catriona Ha - Oxford Handbook of Clinical Medicine (2017, Oxford University Press) - libgen.li.pdf(pp. 667)[context]
  • [Williams, Bailey and Love's Short Practice of Surgery] Norman Williams, Christopher Bulstrode, P Ronan O'Connell - Bailey & Love's Short Practice of Surgery 26E (2013, CRC Press) - libgen.li.pdf(pp. 129)[context]
  • [Williams, Bailey and Love's Short Practice of Surgery] Norman Williams, Christopher Bulstrode, P Ronan O'Connell - Bailey & Love's Short Practice of Surgery 26E (2013, CRC Press) - libgen.li.pdf(pp. 1395)[context]
  • [Williams, Bailey and Love's Short Practice of Surgery] Norman Williams, Christopher Bulstrode, P Ronan O'Connell - Bailey & Love's Short Practice of Surgery 26E (2013, CRC Press) - libgen.li.pdf(pp. 1394, 1395)[context]
  • [Williams, Bailey and Love's Short Practice of Surgery] Norman Williams, Christopher Bulstrode, P Ronan O'Connell - Bailey & Love's Short Practice of Surgery 26E (2013, CRC Press) - libgen.li.pdf(pp. 128, 129)[context]
  • [Williams, Bailey and Love's Short Practice of Surgery] Norman Williams, Christopher Bulstrode, P Ronan O'Connell - Bailey & Love's Short Practice of Surgery 26E (2013, CRC Press) - libgen.li.pdf(pp. 1395, 1396)[context]
  • [Williams, Bailey and Love's Short Practice of Surgery] Norman Williams, Christopher Bulstrode, P Ronan O'Connell - Bailey & Love's Short Practice of Surgery 26E (2013, CRC Press) - libgen.li.pdf(pp. 1395)[context]
  • [Williams, Bailey and Love's Short Practice of Surgery] Norman Williams, Christopher Bulstrode, P Ronan O'Connell - Bailey & Love's Short Practice of Surgery 26E (2013, CRC Press) - libgen.li.pdf(pp. 128)[context]
  • [Williams, Bailey and Love's Short Practice of Surgery] Norman Williams, Christopher Bulstrode, P Ronan O'Connell - Bailey & Love's Short Practice of Surgery 26E (2013, CRC Press) - libgen.li.pdf(pp. 129)[context]
  • [Williams, Bailey and Love's Short Practice of Surgery] Norman Williams, Christopher Bulstrode, P Ronan O'Connell - Bailey & Love's Short Practice of Surgery 26E (2013, CRC Press) - libgen.li.pdf(pp. 127, 128)[context]
  • [Williams, Bailey and Love's Short Practice of Surgery] Norman Williams, Christopher Bulstrode, P Ronan O'Connell - Bailey & Love's Short Practice of Surgery 26E (2013, CRC Press) - libgen.li.pdf(pp. 128)[context]

Sources

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