Undescended testicle (cryptorchidism): what it is, risks and when to operate

Cryptorchidism, or undescended testicle, is the failure of one or both testicles to descend into the scrotum. It is the most common genital malformation in boys: during fetal life the testis travels from the kidney to the scrotum through the inguinal canal, and if this journey is interrupted the testis remains “hidden” along the way. At birth it is very common and often resolves on its own within the first year; if it does not, it must be treated, because a retained testis carries a higher risk of fertility problems and of cancer.

What it is and where the testis lies

In cryptorchidism the testis can stop at any point along the path it normally travels during fetal life, from the lower pole of the kidney to the scrotum. Most often it is found in the subcutaneous tissue of the groin or within the inguinal canal. In these cases only one testis is present in the scrotum (the one that descended normally) and the other is “hidden”.

We speak of testicular ectopia when the testis lies at a point outside the expected descent path. Cryptorchidism more often involves the right testis (about 70% of cases) and can be associated with other genitourinary anomalies, such as hypospadias.

How common it is

Cryptorchidism is found in 3-5% of full-term newborns and in a much higher proportion of preterm babies (up to 9-30%). It is therefore very common at birth, but in most cases it resolves spontaneously within the first year of life, with the natural descent of the testis into the scrotum without any treatment. It is the failure to descend beyond the first year that is considered pathological and requires treatment.

Causes

The causes of cryptorchidism are congenital: they depend on the failed formation or activation of the structures and factors (largely hormonal) that guide the development and descent of the testis during fetal life.

Why it must be treated: fertility and cancer risk

To function properly, the testis needs a temperature lower than the body's: the scrotum provides the cooler environment it requires. A retained testis is about 1 degree warmer than a normally-placed one, and this damages it over time. From this come the two main problems:

• Reduced fertility: the higher temperature impairs sperm production. This is why the testis should be repositioned into the scrotum before puberty
• Increased risk of testicular cancer: cryptorchidism is a recognised risk factor for malignant transformation, and the risk persists even after correction

If surgery is performed late, the chances of functional recovery are lower or nil. In such cases the retained testis is sometimes removed, both to reduce the cancer risk and because the healthy opposite testis may function better in the absence of the cryptorchid one.

Diagnosis

Diagnosis is in most cases clinical: the parent or paediatrician notices the absence of the testis from the scrotum, and the specialist, by gently palpating the inguinal canal, locates the retained testis. Cryptorchidism itself is asymptomatic (painless): the onset of acute pain should instead suggest testicular torsion and requires urgent assessment.

Treatment

Cryptorchidism is treated in childhood, with the aim of preventing fertility damage and improving the chance of early diagnosis of a possible tumour. There are two routes:

• Medical (hormonal) therapy: to be considered within the first year of life
• Surgery (orchidopexy): indicated if the testis has not descended spontaneously by the first year. It consists of repositioning and fixing the testis in the scrotum

Timing is decisive: acting early, before puberty, gives the best chance of preserving testicular function.

Frequently asked questions about the undescended testicle

Does an undescended testicle resolve on its own?

Often yes, but only in the first year of life. At birth cryptorchidism is very common and in most cases the testis descends spontaneously into the scrotum within the first months. If descent does not occur within the first year, the condition is considered pathological and must be treated: waiting longer is no longer reasonable.

At what age is cryptorchidism operated on?

When the testis has not descended within the first year of life, treatment is carried out in childhood, in any case before puberty. Hormonal therapy is considered within the first year; surgical correction (orchidopexy) follows if the testis has not descended. The earliness of the intervention is the factor that most affects the fertility outcome.

Does cryptorchidism cause infertility?

It can reduce fertility, especially if untreated in time or if bilateral, because the higher temperature damages sperm production. A unilateral cryptorchidism corrected early has much less impact. Repositioning the testis before puberty is precisely what protects future fertility.

Do those who have had cryptorchidism have a higher risk of testicular cancer?

Yes. Cryptorchidism is a recognised risk factor for testicular cancer, and the risk persists even after surgical correction. This is why anyone who has had an undescended testicle should regularly perform self-examination and, where appropriate, periodic checks, even in adulthood.

What is the difference between cryptorchidism and testicular ectopia?

In cryptorchidism the testis stops along the normal descent path (from the kidney to the scrotum), typically in the inguinal canal. In testicular ectopia, instead, the testis lies in a position outside this path. The distinction is clinical and is made by the specialist during the examination.

Have you noticed a testicle missing from your child's scrotum? A specialist assessment is advisable: ask Prof. Natali for a consultation or book an appointment at his practices in Florence and Empoli, Italy.

The information on this page is provided for general educational purposes and does not replace a medical examination, which remains the only diagnostic tool for correct and effective treatment.