Atlas of pathophysiology, 2 Edition

Part II - Disorders

Genital Diseases


Cryptorchidism is a congenital disorder in which one or both testes fail to descend into the scrotum, remaining in the abdomen or inguinal canal or at the external ring. Although this condition may be bilateral, it more commonly affects the right testis. True undescended testes remain along the path of normal descent; ectopic testis deviate from that path.

Undescended testes are susceptible to neoplastic changes. The risk of testicular cancer is greater for men with cryptorchidism than for the general male population.

Age Alert

Cryptorchidism occurs in 30% of premature male neonates but in only 3% of those born at term. In about 80% of affected infants, the testes descend spontaneously during the first year; in the rest, the testes may descend later. If indicated, surgical therapy is successful in up to 95% of the cases if the infant is treated early enough.


Primary cause unknown

Possible causes

·   Testosterone deficiency resulting in a defect in the hypothalamic-pituitary-gonadal axis, causing failure of gonadal differentiation and gonadal descent

·   Structural factors impeding gonadal descent, such as ectopic testis or short spermatic cord

·   Genetic predisposition in a small number of cases; greater incidence of cryptorchidism in infants with neural tube defects

·   In premature neonates—early gestational age; normal descent of testes into the scrotum is in seventh month of gestation


A prevalent but still unsubstantiated theory links undescended testes to the development of the gubernaculum, a fibromuscular band that connects the testes to the scrotal floor and probably helps pull the testes into the scrotum by shortening as the fetus grows. Normally in the male fetus, testosterone stimulates the formation of the gubernaculum. Thus, cryptorchidism may result from inadequate testosterone levels or a defect in the testes or the gubernaculum. Because the undescended testis is maintained at a higher temperature, spermatogenesis is impaired, leading to reduced fertility.

Signs and symptoms

Unilateral cryptorchidism

·   Testis on affected side not palpable in scrotum; scrotum underdeveloped

·   Enlarged scrotum on unaffected side due to compensatory hypertrophy (occasionally)

Uncorrected bilateral cryptorchidism

·   Infertility after puberty despite normal testosterone levels

Diagnostic test results

Physical examination confirms cryptorchidism after sex is determined by these laboratory tests:

·   Buccal smear (cells from oral mucosa) determines genetic sex (a male sex chromatin pattern).

·   Blood test of serum gonadotropin level confirms the presence of testes by showing presence of circulating hormone.


Age Alert

If the testes don't descend spontaneously by age 1, surgical correction is generally indicated. Surgery should be performed before age 2; by this time about 40% of undescended testes can no longer produce viable sperm.

·   Orchiopexy to secure the testes in the scrotum and prevent sterility, excessive trauma from abnormal positioning, and harmful psychological effects (usually before age 4 years; optimum age, 1 to 2 years)

·   Human chorionic gonadotropin I.M. to stimulate descent (rarely); ineffective for testes located in the abdomen





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