Cryptorchi­dism: undescended testicle

Objectives

After this course you will be able to

• Classify cryptorchidism: palpable and nonpalpable, congenital and acquired, retractile testis.
• Examine the scrotum with the correct technique and document the finding.
• Know when the child should be referred: if spontaneous descent has not occurred by 6 months of age.
• Explain why ultrasound and hormonal therapy are not recommended.
• Recognize when urgent endocrine and genetic evaluation (DSD) is needed.
• Give parents accurate information about fertility and tumor risk.

Basics

Cryptorchidism in numbers

• 1–4.6%of full-term boys
• Up to 45%of preterm boys
• ~1%still undescended at 1 year
• ~20%share of nonpalpable testes

Most testes that are undescended at birth descend on their own in the first months, mainly during mini-puberty. Spontaneous descent usually occurs by 6 months of age (corrected age in preterm infants); after that it is very unlikely.

About one third of cases are bilateral. Bilateral and especially nonpalpable testes, and cases associated with hypospadias, require particular attention.

Basics

Embryology: how does the testis descend?

Testicular descent proceeds in two phases:

1. Transabdominal phase (weeks 8–15 of gestation): under the influence of INSL3 and swelling of the gubernaculum, the testis moves toward the internal inguinal ring.
2. Inguinoscrotal phase (weeks 25–35): under the influence of androgens and the genitofemoral nerve (CGRP), the testis descends through the inguinal canal into the scrotum.

Disruption of either phase causes the testis to stop at some point along its path. The sharp increase in cryptorchidism risk with preterm birth is explained by the late completion of the second phase.

Basics

Classification

Basics

What happens if it is not treated?

• Fertility: in an undescended testis, the number of germ cells begins to decline after the first year of life. Fertility is more affected in bilateral cryptorchidism.
• Tumor risk: the risk of testicular tumor is increased several times. Early orchiopexy, performed before puberty, reduces this risk and makes the testis accessible for examination.
• Torsion and trauma: an inguinal testis is more susceptible to torsion and injury.
• Inguinal hernia: a patent processus vaginalis often accompanies cryptorchidism.
• Psychological impact: an empty scrotum causes distress in adolescence.

Diagnosis

History

• Gestational age and birth weight.
• Was the testis in the scrotum at birth? Notes from the newborn examination are very valuable.
• Was it previously seen in the scrotum and later "lost"? This suggests an acquired or retractile testis.
• Family history of cryptorchidism, hormonal drugs during pregnancy.
• Inguinal or scrotal surgery (iatrogenic ascent after inguinal hernia repair).

Diagnosis

Examination technique

1. Warm room, warm hands. The child should be calm and relaxed.
2. Inspect first: is the scrotum symmetric, is it well developed?
3. The child lies supine with legs in the "frog-leg" position. Older children may also be examined sitting or squatting.
4. One hand "milks" downward along the inguinal canal starting from the internal inguinal ring, while the other hand tries to catch the testis in the scrotum.
5. If the testis is caught, it is gently brought down into the scrotum and released: if it stays there, it is retractile; if it immediately ascends, it is undescended.
6. Both sides, testicular size, the status of the contralateral testis and the penis (hypospadias, micropenis) are documented.

Diagnosis

Is ultrasound needed?

For a nonpalpable testis, the diagnostic standard is examination under anesthesia and diagnostic laparoscopy. Laparoscopy establishes the diagnosis and allows treatment to begin in the same session.

Sending the child for ultrasound and waiting for the result only delays referral. The child should be referred to a pediatric urologist regardless of the ultrasound result.

Diagnosis

When should DSD be considered?

• The most important danger: a virilized 46,XX girl with congenital adrenal hyperplasia (CAH). A salt-wasting crisis is life-threatening.
• Evaluation: karyotype, 17-OH progesterone, electrolytes, joint assessment with an endocrinologist and a pediatric urologist.
• In bilateral nonpalpable testes, AMH (anti-Müllerian hormone) and inhibin B are used to check for anorchia.

Treatment

Timing of referral and surgery

1. Undescended testis at birth: document it, inform the parents.
2. Re-examine at 3–6 months.
3. If still not in the scrotum at 6 months (corrected age): refer to a pediatric urologist.
4. Orchiopexy: at 6–12 months, no later than 18 months.

Cryptorchidism found at a later age, as well as an acquired (ascending) testis, is operated on as soon as possible after diagnosis.

Treatment

Hormonal therapy

Some centers use GnRH after surgery in bilateral cryptorchidism to preserve fertility, but this approach is not a routine recommendation and is a decision for the pediatric urologist and endocrinologist.

Treatment

Surgical approach

For a palpable testis the success rate is above 95%. The main complications are testicular atrophy and reascent. The risk of atrophy is higher with the Fowler-Stephens operation.

Treatment

Long-term follow-up

• The position and size of the testis are checked during the first year after surgery.
• A retractile testis is checked once a year until puberty.
• The adolescent is taught testicular self-examination.
• The family is given balanced information about fertility and tumor risk: early surgery reduces both risks but does not eliminate them.