Purpose or Case Report: To describe the ultrasonographic appearances of the gubernaculum in boys, review its utility in diagnosing cryptorchidism and provide a functional illustration of the gubernaculum as it conducts the testis into the scrotum. We will elucidate this process with a review of the relevant embryology.
Methods & Materials: This is a retrospective review of 26 imaging studies obtained as part of scrotal ultrasound evaluations of male patients for cryptorchidism, infection and masses, between 2007-2016. High-resolution linear ultrasound probes were used to demonstrate the scrotum, inguinal canal, pelvis and abdomen to evaluate the pathway of descent of the testis so that the undescended testis might be located. The gubernaculum was identified in this process. The patients were referred from NICU, maternity unit and outpatient settings.
Results: These 26 male patients ranged in age from 0 days to 59 months. We examined 4 preterm and 22 full term patients. 23/26 had undescended testes. Bilateral undescended testes were seen in 20/23 patients and a unilateral undescended testis in 3/23 patients. The gubernaculum was identified in 23/26 patients. It was seen bilaterally in 15/26 patients, of whom 12/15 were cryptorchid and 3/15 were descended. The gubernaculum was seen unilaterally in 8 cryptorchid boys. This provides a total of 38 gubernacula. It was not seen in 3 cryptorchid boys.

The gubernaculum is homogeneous in echogenicity and less echogenic than the adjacent testis. The echo-pattern is loosely aggregated. It is soft and compressible. It is not vascular on color Doppler evaluation. It has a slippery behavior and variable shape. In cross-section, it’s size is similar to or slightly greater than the testis. It lies distal to and contiguous with the testis. It can be demonstrated passing to and through the internal (deep) ring, into the inguinal canal and to the base of the scrotum, therefore it’s length varies. It should not be confused with the testis as it does not have the characteristic testicular features of a mediastinum testis or strictly ovoid configuration.
Conclusions: The gubernaculum is a normal embryological structure not often described in the pediatric radiological literature. Confident demonstration of the gubernaculum can assist in locating the undescended testis and provides a more detailed diagnosis of cryptorchidism. Ultrasonographic demonstration of the arrested process of testicular descent also provides a beautiful illustration of the normal physiological mechanism of descent.