Retractile testicle: what it is and what to expect

Each testicle is attached to a thin muscle called the cremaster. When that muscle contracts, the testicle is drawn up towards the body, and when it relaxes, the testicle can drop back. Children's Hospital of Philadelphia, a US paediatric centre, calls this the cremasteric reflex and says it is seen in all males, though it may be more obvious in some children than in others.

The European Association of Urology (EAU) paediatric guideline defines retractile testes as ones that have completed their descent into a proper scrotal position but can be found again higher along the path of their normal descent. They can be easily manipulated down into the scrotum and remain there at least temporarily.

The two are often confused because the scrotum may look empty in both. The NHS explains that undescended testicles are where the testicles are not in the usual place in the scrotum, and that the main sign is not being able to feel 2 round glands in the scrotum. It says undescended testicles are usually found at the newborn physical examination.

A retractile testicle, in contrast, has descended and can be felt in the scrotum at times. Children's Hospital of Philadelphia says that an undescended testicle is not felt in the scrotum at all, while a retractile one is in the scrotum but can be pulled back. The practical test is whether the testicle can be guided into the scrotum, and stay there without being held.

Children's Hospital of Philadelphia says the reflex can be triggered by cold, fear or a light touch to the inside of the thigh. This is why a boy may look different in a warm bath from how he looks in a cold room or when anxious at a medical appointment. Boys generally have no symptoms, and at home it may simply seem that the scrotum looks empty and the testicles cannot be seen.

Because the reflex is easily triggered, examination technique matters. The same source notes that certain positions reduce the reflex, such as sitting cross-legged or squatting, and that it helps if the boy is as relaxed as possible.

It is diagnosed by physical examination, not by scans or blood tests. Children's Hospital of Philadelphia says that as long as the testicle can be easily guided into the scrotum and remain there on its own, without tension, the testicles are considered retractile. A parent cannot reliably make this call at home, because a cold or tense child will look different from a relaxed one.

The EAU guideline adds that a history of testes that were previously in the scrotum can suggest a retractile testis or a testis that has later moved up. If the testicle cannot be brought down, or springs straight back, the diagnosis changes and the boy is managed as having an undescended or ascended testicle.

A retractile testicle is harmless in itself, but it is not always permanent. The EAU guideline says retractile testes carry a higher risk of secondary ascent, up to 33%, and recommends yearly checks until puberty. Children's Hospital of Philadelphia describes an ascending testicle as one where the attachment of the testicle to the scrotum lengthens and the testicle is pulled out of position as the child grows.

The same guideline states that ascending testes can affect fertility potential, though to a lesser extent than congenital undescended testes. That is the reason for checking, not a reason for alarm. A boy with a retractile testicle should be examined yearly by a doctor, and seen by a urologist if there is any concern about position.

Parents can help by mentioning any change they notice: a testicle that now seems always high, that cannot be coaxed down, or that looks smaller than the other side.

The EAU guideline recommendation is not to offer medical or surgical treatment for retractile testes. Children's Hospital of Philadelphia likewise says that surgery is not recommended for retractile testicles.

If a testicle ascends and can no longer be brought into the scrotum, the approach changes. The NHS says boys with undescended testicles may need surgery to move them to the correct place, called orchidopexy, usually when around 1 year old. For an older boy whose testicle has ascended, a paediatric urologist will advise on timing.

See a GP if you think your son has a testicle that is not in the usual place, or if you notice any change in his testicles that is not usual, as the NHS advises. A sudden, severe pain in the scrotum, with swelling or vomiting, is an emergency. Call 999 or go to A&E, because a twisted testicle needs urgent treatment.

Reassurance and routine follow-up are often all that is needed. Private paediatric urology services exist as well as NHS referral, and the guidance on examination and follow-up is the same.