From the Guidelines
For a suspected undescended testicle, order a scrotal and inguinal ultrasound to evaluate the testicular presence, location, size, and blood flow to both testes. This combined study will allow visualization of both the scrotum and the inguinal canal, which are the most common locations for undescended testes 1. When ordering, indicate the clinical concern for cryptorchidism (undescended testicle) and specify that both the scrotal contents and inguinal regions need to be examined.
The most recent and highest quality study, published in 2022, recommends ultrasound as the initial imaging modality for newly diagnosed palpable scrotal abnormality, which includes suspected undescended testicles 1. This approach is non-invasive, doesn't use radiation, and can effectively locate an undescended testicle in most cases, particularly if it's in the inguinal canal. However, be aware that ultrasound has limitations in detecting intra-abdominal testes, so a negative ultrasound doesn't completely rule out cryptorchidism if the testicle is located higher in the abdomen.
Key points to consider when ordering the ultrasound include:
- Specify the clinical concern for cryptorchidism (undescended testicle)
- Request evaluation of both the scrotal contents and inguinal regions
- Ask for assessment of testicular presence, location, size, and blood flow to both testes
- Be aware of the limitations of ultrasound in detecting intra-abdominal testes
By following this approach, you can effectively use ultrasound as an initial diagnostic step when urology consultation is not immediately available, as in your case where urology is 3 hours away.
From the Research
Ultrasound Examination for Undescended Testicle
To determine the appropriate ultrasound examination for a suspected undescended testicle, consider the following points:
- The primary goal of imaging is to locate the testicle and assess its position, rather than to diagnose the condition itself 2.
- Ultrasound is the preferred imaging method for cryptorchidism, but its value is questionable according to most guidelines 3.
- A study on three-dimensional ultrasonography suggests that it can be useful in preoperative and postoperative assessment of the undescended testis, particularly in evaluating testicular volume and mobility 3.
- However, international guidelines do not recommend ultrasonography or other diagnostic imaging for undescended testis, as they cannot add diagnostic accuracy or change treatment 2.
Recommended Ultrasound Examination
Based on the available evidence, if an ultrasound is to be ordered, consider the following:
- A scrotal ultrasound to assess the presence and position of the testicle.
- An inguinal ultrasound to evaluate the inguinal canal and rule out an inguinal hernia, which can be mistaken for an undescended testis 2.
- A three-dimensional ultrasound may be considered for preoperative and postoperative assessment of the undescended testis, particularly in evaluating testicular volume and mobility 3.
Important Considerations
Keep in mind that:
- Early diagnosis and management of the undescended testicle are crucial to preserve fertility and improve early detection of testicular malignancy 4.
- Referral to a pediatric urologist or other qualified subspecialist is recommended by six months of age, or earlier in certain cases 4.
- Testicular torsion is a potential complication of undescended testis, and prompt diagnosis and treatment are essential to preserve the testicle 5.