Pathology > Study Images > Male Genitals > Testis > Congenital Anomalies
Objectives Anat & Hist Congenital Vascular Neoplasms

II. Congenital Anomalies

Objectives:

After completing this section you will know:

  • the gross and histologic features of undescended testis
  • the clinical implications of the abnormality
  • the correct procedure when crytorchidism is detected in an adult and why

  1. Cryptorchidism (Undescended testis)

This is the failure of the testis to descend normally into the scrotum. Descent may be arrested at any point along the normal path from abdomen to upper scrotum. About 4% of newborn, full-term males have a cryptorchid testis, but in the majority the testis descends into the scrotum so that incidence drops to less than 1% in adults. The condition is commonly unilateral but may be bilateral in about 25% of cases and is slightly more common on the right. The reasons for the failure of the testis to descend are not known.

The cryptorchid testis undergoes progressive atrophy and is small in size and firm in consistency. Histologically, the changes range from a reduction in number of germ cells to complete absence of germ cells with hyalinization and thickening of the seminiferous tubular basement membrane and stromal fibrosis. Finally, the tubules appear as hyalinized cords of connective tissue with surrounding prominent basement membranes. Leydig cells appear in prominent nodules in the interstitium. The scrotal testis of patients with unilateral cryptorchidism may show similar histologic changes.

There are two important sequelae of this condition. Failure of spermatogenesis in the cryptorchid testis due to the high temperature of the non-scrotal tissues and reduction in germ cells in the scrotal testis result in infertility. More ominous is the increased risk for development of testicular germ cell tumors (see below). The higher the cryptorchid testis is arrested in its descent, the greater the risk of subsequent germ cell tumor. Orchiopexy (surgical fixation of the testis in the scrotum) should be performed early. The protective effect of orchiopexy is difficult to evaluate, as there have been reports of germ cell tumors arising in testes surgically positioned in the scrotum at an early age. However, most studies that early orchiopexy reduces the risk of germ cell tumor. For this reason, an undescended testis discovered in an adult should be removed.

Objectives Anat & Hist Congenital Vascular Neoplasms