Cryptorchidism

Cryptorchidism refers to an absence of a testis (or testes) in the scrotal sac. It may refer to an undescended testis, ectopic testis, or an atrophic or absent testis. Correct localisation of testes is essential because surgical management varies on location.

The testes develop in the abdomen and at ~21 weeks of gestation and migrate toward the inguinal canal through the deep inguinal ring. The migration is complete at ~30 weeks. The gubernaculum is the ligament which connects the testes to the scrotum. Under hormonal influence (probably testosterone), the gubernaculum contracts, and the testes descend into the scrotum. Causes/associations of undescended testes are:

Ultrasound

Ultrasound has 45% sensitivity, 78% specificity, and 88% accuracy for localisation of an undescended testis and is more accurate than clinical examination 4,5.

  • lack of a testicle in the scrotal sac
  • the undescended testis is homogeneously hypoechoic ovoid structure, similar to contralateral testis, with an echogenic mediastinum teste
  • the ectopic testis may be high up in scrotum or within inguinal canal (39%)
  • ultrasound is limited in intra-abdominal, pelvic or retroperitoneal/ectopic testes (20%)
  • ultrasound is also inconclusive in evaluation of atrophic testis (41%), where it is difficult to differentiate from lymph nodes or pars infravaginalis gubernacula 1
MRI

MRI is the best cross-sectional modality to assess crypto-orchidism (replacing CT scan). It has a higher sensitivity than ultrasound (~90%) and a higher specificity (100%) 6.

Coronal T1W images can show gubernaculum testes and spermatic cord, which can be followed to locate the undescended testes. Also, ectopic pelvic or retroperitoneal location of testes can be identified. Diffusion-weighted MRI shows markedly hyperintense testes, and helps to differentiate it from surrounding structures 2.

Most undescended testes at birth descend in the first three months after birth

Orchiopexy is the preferred mode of management in case of viable testes high-up in scrotum or within inguinal canal / abdomen. It is performed after 1 year of age since the testes may descend without intervention.

With cryptorchidism there is 32x increased risk of developing a testicular germ cell tumour, with an incidence of 1 in 2000 (higher in bilateral cases, and in abdominal cryptorchidism) 7. The effect of surgical correction  decreasing the risk of malignancy is controversial but it does allow for easier examination 7, and hopefully earlier detection. 

An exaggerated cremasteric reflex can simulate cryptorchidism.


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Article Information

rID: 16174
System: Urogenital
Section: Pathology
Synonyms or Alternate Spellings:
  • undescended testis
  • Undescended testes

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Cases and Figures

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     Case 1
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    Ectopic testis
    Case 2: ectopic testes with torsion
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    Case 3: right undescended testicle
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    Case 4
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    Case 5: bilateral intra-abdominal
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    Case 6: left
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    Case 7: with malignant transformation
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