Undescended and Maldescended Testes

Normal testicular development in utero begins along the mesodermal ridge of the posterior abdominal wall. By the 7th month, the right and left testes reach their respective inguinal canals and by 9 months, each testis has usually reached the scrotum.

An undescended testis is a testis that is absent from the scrotum. The term cryptorchidism, from the Greek kryptos (hidden) and orchis (testicle) is also used. Absence may be due to:

• Testicular agenesis (anorchia) - uncommon
• Retractile testis
• The Ascending testis syndrome
• Testicular maldescent

Retractile testes

• Prepubertal boys can have an exaggerated cremasteric reflex.
• The testis may retract out of the scrotum in the cold, on examination, on excitement or on physical activity.
• It is normal and will descend when relaxed and warm, or it can be manipulated back into the scrotum.
• Retractile testes do not need any treatment but do need close follow-up until puberty.¹
• In one study, retractile testes had a 32% risk of becoming an ascending or acquired undescended testis.²

The Ascending testis syndrome

• A previously normal or a retractile testis can become high with a shortened spermatic cord that prevents the testis from staying in the scrotum.
• Usually diagnosed aged 8-10 years.
• Needs corrective treatment.³

Maldescended testes

• Are usually unilateral.
• The scrotum may be underdeveloped.
• Maldescent may be due to an anatomical abnormality or due to hormone lack or resistance. The release of testosterone from the fetal testis, the release of substances from an intact genitofemoral nerve and gonadotrophin hormone have all been cited as having possible involvement in normal testicular descent.
• Descent can be:
  • Arrested - Descent is along the normal path but incomplete. The testis may be located near the pubic tubercle, in the inguinal canal (80%)⁴ or uncommonly in the abdomen. The testis is often small and abnormal with a short spermatic cord. May be associated inguinal hernia.
  • Ectopic - Descent deviates from the normal path. The testis is most often found in the superficial inguinal pouch. Perineal, abdominal, pelvic, crural, penile and femoral positions also all possible. Testis and spermatic cord usually normal.

• Most common congenital anomaly of the male genitalia.⁵
• Affects 6.7% of boys at birth.⁶
• Higher incidence in premature babies (up to 25%).³
• Affects almost 1% of all full-term male infants at the age of 1 year.⁵
• Unilateral cryptorchidism is 4 times more likely than bilateral.
• Right testis is more likely to be affected than left.

• Is by physical examination.
• Imaging or ultrasound does not add any benefit to differentiating between palpable and non-palpable testes.¹
• Examination should take place while the child is supine and in a cross-legged position.¹
  1. Perform a visual examination of the scrotum.
  2. Inhibit the cremasteric reflex with one hand above the symphysis in the groin region before touching the scrotum.
  3. 'Milking' of the groin region towards the scrotum may help to move the testis into the scrotum.
  4. A retractile testis can usually be moved into the scrotum and will remain there until it retracts back into the groin again with a cremasteric reflex (e.g. touching the inner thigh).
  5. Look at the femoral, penile and perineal region for ectopic testes.

Syndromes associated with cryptorchidism

• Prader-Willi
• Kallmann's
• Laurence-Moon-Biedl
• Intersexuality/Congenital Adrenal Hyperplasia
• Prune belly

• Treatment should be completed by 12-18 months of age.¹
• Testes are unlikely to spontaneously descend after 1 year of age.
• There is potential for loss of testicular quality after age 1 which can affect fertility.

Medical Treatment

• Testicular descent is hormonally dependent.
• Treatment with human chorionic gonadotrophin (hCG) or gonadotrophin-releasing hormone (GnRH) can be used.
• Success rates are best the lower the undescended testis is located.
• Maximum success rates are 20%.^7,8
• Medical treatment may also be useful before or after surgery and may have an beneficial effect on later fertility.¹
• Side effects of hCG treatment can include enlargement of the penis, pubic hair growth, increased testicular size and aggressive behaviour during treatment.⁹

Surgical treatment

• If the testis is palpable: Inguinal approach used. Orchidopexy can be performed. Success rate up to 92%.¹⁰ Orchidopexy involves mobilization of the testis on its essential structures (the vas, the testicular vessels and the spermatic cord) so that the testis can be brought down into the scrotum. The testis may also be fixed within the scrotum.
• If the testis is non-palpable: Examination under anaesthetic may reveal the previously non-palpable testis. If not, inguinal surgical exploration ± laparoscopy is needed. Every attempt should be made to locate the non-palpable testis. It is likely that the testis will be found just through the inguinal incision but laparoscopy may be needed to search the abdomen. Removal, orchidolysis or orchidopexy can then be performed laparoscopically.

• Increased risk of testicular torsion. May be associated with the development of a testicular tumour. Torsion of an intra-abdominal testis may present as an acute abdomen.¹¹
• Increased risk of testicular trauma.

Affect on fertility

• Boys with one undescended testis have a lower fertility rate but the same paternity rate as boys with bilateral descended testes.¹
• Boys with bilateral undescended testes have lower fertility and paternity rates.¹

Risk of testicular malignancy

• There is a 20 x increased risk of developing testicular malignancy in boys with an undescended testis.¹
• This is not reduced once treatment for the undescended testis has been carried out.¹

Cosmetic appearance

• Surgical transfer of the testis into the scrotum produces a better cosmetic appearance.
• Prostheses may be used if the testis is removed. Prostheses should be implanted during adolescence.

Screening

• The 'National Screening Committee Policy - Cryptorchidism screening' was last updated in July 2006. Screening for undescended and maldescended testes should take place in the routine physical examination of boys within 72 hours of birth and at the 6-8 week check.¹²
• Screening is also recommended for boys with a history of undescended testis during and after puberty because of the risk of testicular malignancy.¹