From the Guidelines
Physical examination is the cornerstone of diagnosis for undescended testis (cryptorchidism), and it should be performed in a warm environment with the child relaxed, using warm hands to prevent cremasteric reflex contraction. The examination should include palpation of the testes for quality and position at each recommended well-child visit 1. Approximately 70% of undescended testes are palpable on careful examination. When physical examination is inconclusive, ultrasound should not be used as the initial imaging modality, as it has limited sensitivity for non-palpable testes and rarely assists in decision making 1. For non-palpable testes, diagnostic laparoscopy is considered the gold standard, allowing direct visualization of intra-abdominal testes or confirming testicular absence.
Some key points to consider in the diagnosis of cryptorchidism include:
- Obtaining gestational history at initial evaluation of boys with suspected cryptorchidism 1
- Referring infants with a history of cryptorchidism who do not have spontaneous testicular descent by six months (corrected for gestational age) to an appropriate surgical specialist for timely evaluation 1
- Referring boys with the possibility of newly diagnosed (acquired) cryptorchidism after six months (corrected for gestational age) to an appropriate surgical specialist 1
- Using ultrasound as the established first-line imaging modality for acute scrotal disease, but not for routine evaluation of cryptorchidism 1
It's also important to note that early diagnosis is crucial, ideally before 6 months of age, as timely intervention reduces risks of infertility, testicular malignancy, and torsion associated with cryptorchidism. Karyotyping is not typically used in the diagnosis of undescended testis, unless there are other indications of a genetic disorder. Laparoscopy is a valuable tool in the diagnosis and treatment of non-palpable testes, but it should only be performed by an experienced surgeon. Ultrasound, on the other hand, has limited utility in the diagnosis of cryptorchidism, but it can be useful in evaluating other scrotal disorders.
From the Research
Diagnostic Methods for Undescended Testis
The diagnostic methods for an undescended testis (cryptorchidism) include:
- Laparoscopy: a minimally invasive surgical procedure that allows for the visualization of the testes and surrounding tissues 2
- Ultrasound: a non-invasive imaging modality that can be used to locate the testes, but has variable sensitivity and specificity 3, 4
- Magnetic Resonance Imaging (MRI): a non-invasive imaging modality that can be used to localize and characterize non-palpable testes, but is not sensitive enough for complete exclusion of the diagnosis of an undescended testis 5, 3
- Magnetic Resonance Angiography (MRA): a non-invasive imaging modality that can be used to localize impalpable undescended testes with high sensitivity and specificity 3
- Karyotyping: a genetic test that can be used to identify chromosomal abnormalities in patients with undescended testes and ambiguous genitalia 2
Advantages and Limitations of Each Method
- Laparoscopy: advantages include high sensitivity and specificity, ability to diagnose and treat impalpable testes in a single procedure, and minimal invasiveness 2. Limitations include the need for surgical expertise and equipment.
- Ultrasound: advantages include non-invasiveness and wide availability 4. Limitations include variable sensitivity and specificity, and inability to localize non-palpable testes in some cases 3, 4
- MRI and MRA: advantages include high sensitivity and specificity, and ability to characterize non-palpable testes 5, 3. Limitations include high cost, limited availability, and need for sedation in pediatric patients 4
- Karyotyping: advantages include ability to identify chromosomal abnormalities in patients with undescended testes and ambiguous genitalia 2. Limitations include limited availability and high cost.
Clinical Scenarios for Diagnostic Imaging
Diagnostic imaging is not recommended for routine evaluation of boys with cryptorchidism, but may be necessary in certain clinical scenarios, such as: