Undescended Testes
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  • Undescended testes (aka cryptorchidism, and sometimes maldescended testes) can be congenital or acquired
  • Usually unilateral
  • Congenital undescended testes affects approximately 3-6% of males at birth
    • <1% remain undescended by the age of 1 year
    • Up to 30% of premature infants
  • Most resolve spontaneously within the first few months of life
  • Testes are surgically descended usually around 6 months if they do not descend by themselves
  • Leaving testes undescended increases the risk of malignancy and infertility
  • Acquired undescended tests occurs between the age of 1 and 7, whereby the spermatic cord does not grow at the same rate as the child
  • Can be confused for a retractile testes


  • Testes normally descend in the 8th month of pregnancy
  • Some boys have delayed testicular descent – but most will descend without intervention by the age of 6 months
  • The axact cause is not known, but thought to be multifactorial
  • Most are partially descended and found in the inguinal canal. Only rarely are they seen in the abdomen
    • Rarely they are also seen “ectopically” – i.e. not found along their normal path of descent, e.g. in the inguinal pouch. These testes are usually well developer and of normal appearance
  • Growth of undescended testes may more slowly, due to the higher temperature within the abdomen
  • The increased risk of malignancy in undescended testes only appears to affect testes in the abdominal cavity, and not those in the inguinal canal


  • Can be congenital, or acquired
  • Congenital is often spotted on a new baby check or a 6 week baby check
  • One or both testes will be absent from the scrotum
  • 70% can be located (often in the inguinal canal)


  • Increased risk of testicular torsion – which may present as abdominal pain
  • Reduced fertility, but same paternity rate (for unilateral undescended testes)
  • Reduced fertility and paternity rate (bilateral)
  • 3-4x increased risk of testicular malignancy


  • Examine the scrotum and inguinal canal for the testes
  • Any testes not in the scrotum should be gently manipulated to see if it can be moved into the scrotum (see retractile testes below)
  • In complete absence of the testes, examination under general anaesthetic (EUA) may be performed to assist locating it. If it still cannot be located, then laparoscopy is the procedure of choice. Imaging is not usually indicated

Retractile testes

Retractile testes is a normal variant, sometimes confused for an undescended tests. It a common finding in young boys, secondary to a strong cremasteric reflex, whereby the testicles can be retracted into the inguinal canal – often stimulated by examination of the genitals, cold or excitement. To differentiate this from true undescended testes, you should attempt to find the testes in the inguinal canal, or high up in the scrotum, and gently try to ‘milk’ it down into the scrotum. An undescended testes usually cannot be found, or if palpable in the inguinal canal, cannot be manually moved into the scrotum. A testicle that can be moved into the scrotum (even temporarily), is of normal size, and can reach the bottom of the scrotum is usually a retractile testes. Once placed in the scrotum, a retractile testes will usually remain there until the cremasteric reflex is activated again. A truly undescended testes may be able to be moved into the scrotum but will not stay there of its own accord.

Consider referral for retractile testes that does not resolve as occasionally these can become truly undescended. Monitor until puberty, after which time, ascension is rare.


  • Monitor up to 6 months of age
  • If remains undescended after 6 months, then the child should be referred for surgical managements – orchidoplexy. This is usually performed at about the age of 9 months
  • Orchidoplexy is usually a day procedure.
    • Palpable testes in the inguinal canal – Two incisions are made, one in the inguinal canal and one in the scrotum. The Testes is then pulled down into the scrotum and often fixed in place with sutures
    • Non-palpable testes –examination under anaesthetic followed by laparoscopy if still not located.
  • Orchidoplexy is still a strongly debated topic amongst surgeons
  • Treatment should be performed by 12-18 months to avoid sequelae of undescended testes
  • Complications
    • Failure of procedure – a small percentage will require a second attempt
    • Testicular atrophy – if the testes was originally high up in the abdomen, or has a poor blood supply it can subsequently atrophy once placed in the scrotum


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Dr Tom Leach

Dr Tom Leach MBChB DCH EMCert(ACEM) FRACGP currently works as a GP and an Emergency Department CMO in Australia. He is also a Clinical Associate Lecturer at the Australian National University, and is studying for a Masters of Sports Medicine at the University of Queensland. After graduating from his medical degree at the University of Manchester in 2011, Tom completed his Foundation Training at Bolton Royal Hospital, before moving to Australia in 2013. He started almostadoctor whilst a third year medical student in 2009. Read full bio

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