Undescended Testes (Cryptorchidism)

Summary
Introduction
Differential Diagnosis
Investigation
Management

Summary

refer to surgical services if a palpable UDT fails to descend by 3 months of age or the testis is non-palpable
exclude the diagnosis of ambiguous genitalia

Introduction

Undescended testes (UDT) is a common finding in the neonatal period affecting up to 1 in 20 term males and up to one third of preterm males. In most cases the aetiology is unknown.

The risk of infertility and of testicular malignancy is increased in men with a history of UDT. The UDT is also more vulnerable to trauma and torsion. Histologic changes in the uncorrected UDT are seen at approximately 18 months to 2 years. If at term the testes are normally sited, deep in the scrotum, the infant is unlikely to develop true acquired cryptorchidism.

The UDT may be best classified as palpable or non-palpable. The non-palpable testis is uncommon (less than 10%) with approximately half of these atrophic. The palpable UDT should be defined by the lowest point to which it can be mobilised, with most cases being palpable in the groin. If a testis is not readily identified a finger sweep should be performed from the anterior iliac crest along the inguinal canal whilst palpating the scrotum. The normal testicular volume at term is 1-2cm³.

Differential Diagnosis

UDT in association with severe hypospadias must be assessed for congenital adrenal hyperplasia and other causes of ambiguous genitalia (approximately 25% of neonates with undescended testes and hypospadias have ambiguous genitalia)

an ectopic testis (ie has not followed the normal path of descent) is rare and should be referred for surgical review

Investigation

imaging studies are rarely of use in identifying a non-palpable UDT

immediate referral and further investigations are necessary if undescended testes are associated with ambiguous genitalia

Management

Failure to descend by approximately 3 months of life is considered abnormal and these infants should be referred for surgical opinion. The optimal time for orchidopexy is at about 6 to 12 months of age. This allows for further spontaneous descent but may reduce some of the sequelae of testicular non-descent.

Although surgery to place the testis in the scrotum may not reduce the risk of infertility or malignancy it improves the endocrine function of the testis and facilitates testicular self-examination. It also reduces the risk of torsion and direct trauma.

Surgical exploration (laparoscopy) for the non-palpable testis is warranted as in approximately half of these cases the testis may be salvaged. In the remainder the testis is absent or a testicular remnant with neoplastic potential may be removed. Absence of both testes (anorchia) is rare.

References

Avery, G.B., Fletcher, M.A., and MacDonald, M.G. editors. Neonatology: Pathophysiology and Management of the Newborn. 5^th edition. Lippincott, Williams & Wilkins. 1999.

Hutson, J.M., Woodward, A.A., Beasley, S.W. (editors). Jones’ Clinical Paediatric Surgery, Diagnosis and Management. 5^th edition. Blackwell Science Asia. 1999.

Levene, M.I., Tudehope, D.I., and Thearle, M.J. Essentials of Neonatal Medicine. 3^rd edition. Blackwell Science. 2000.

Ashcraft, K.W., Murphy, J.P., Sharp, R.J., Sigalet, D.L., Snyder, C.L. (editors). Pediatric Surgery. 3^rd edition. W.B. Saunders Company. 2000.