Porth's Essentials of Pathophysiology, 4e

1013

Disorders of the Male Genitourinary System

C h a p t e r 3 9

detection of a testicular malignancy by positioning the testis in a more easily palpable location. As a group, men with unilateral or bilateral cryptor- chidism usually have decreased sperm counts, poorer- quality sperm, and lower fertility rates than do men whose testicles descend normally. The likelihood of decreased fertility increases when the condition is bilat- eral. Early orchiopexy appears to provide some protec- tion of fertility. 60 Diagnosis is based on careful examination of the geni- talia in male infants. Undescended testes due to cryptor- chidism should be differentiated from retractable testes that retract into the inguinal canal in response to an exaggerated cremaster muscle reflex. Retractable testes usually are palpable at birth but later become nonpal- pable. They can be brought down with careful palpa- tion in a warm room. Retractable testes usually assume a scrotal position during puberty. They have none of the complications associated with cryptorchidism. 54 Because imaging has not proven to be 100% reliable, laparoscopy has become standard practice for localiza- tion of nonpalpable testes. The treatment goals for the child with cryptorchidism include measures to enhance future fertility potential, placement of the gonad in a favorable place for cancer detection, and improved cosmetic appearance. Surgical treatment is the cornerstone of therapy. Current infor- mation suggests that placement of the testes in the scrotum should be accomplished by 1 year of age to maximize the potential for fertility. Although hormonal treatment has been used in Europe, randomized clinical trials have not shown it to be effective in stimulating testicular descent. 54 Treatment of men with undescended testis should include lifelong follow-up, considering the sequelae of testicular cancer and infertility. Parents need to be aware of the potential issues of infertility and increased risk of testicular cancer. On reaching puberty, boys should be instructed in the necessity of testicular self-examination.  Changes Related to Aging Like other body systems, the male reproductive sys- tem undergoes degenerative changes as a result of the aging process; it becomes less efficient with age. The declining physiologic efficiency of male reproductive function occurs gradually and involves the endocrine, circulatory, and neuromuscular systems. 61 Compared with the marked physiologic change in aging women, the changes in the aging man are more gradual and less drastic. Gonadal and reproductive failures usually are not related directly to age because a man remains fertile into advanced age; 80- and 90-year-old men have been known to father children. As the man ages, his reproductive system becomes measurably different in structure and function from that of the younger man. Male sex hormone lev- els, particularly testosterone, decrease with age, with the decline starting later on average than in women.

Abdominal

Inguinal canal

High scrotal

Normal

FIGURE 39-14. Possible locations of undescended testicles.

20% of cases. The testes develop intra-abdominally in the fetus and usually descend into the scrotum through the inguinal canal during the seventh to ninth months of gestation. The undescended testes may remain in the lower abdomen or at a point of descent in the inguinal canal (Fig. 39-14). The incidence of cryptorchidism is directly related to birth weight and gestational age; infants who are born prematurely or are small for gestational age have the highest incidence of the disorder. The cause of cryptor- chidism in full-term infants is poorly understood. Most cases are idiopathic, but some may result from genetic or hormonal factors. The major manifestation of cryptorchidism is the absence of one or both of the testes in the scrotum. The testis either is not palpable or can be felt external to the inguinal ring. Spontaneous descent often occurs dur- ing the first 3 months of life, and by 6 months of age the incidence decreases to 0.8%. 54 Spontaneous descent rarely occurs after 4 months of age. In children with cryptorchidism, histologic abnor- malities of the testes reflect intrinsic defects in the tes- ticle or adverse effects of the extrascrotal environment. The undescended testicle is normal at birth, but patho- logic changes can be demonstrated at 6 to 12 months. 54 There is a delay in germ cell development, changes in the spermatic tubules, and reduced number of Leydig cells. These changes are progressive if the testes remain undescended. When the disorder is unilateral, it also may produce morphologic changes in the contralateral descended testis. The consequences of cryptorchidism include infertil- ity, testicular torsion, malignancy, and the possible psy- chological effects of an empty scrotum. 54,59,60 Indirect inguinal hernias usually accompany the undescended testes but rarely are symptomatic. Recognition of the condition and early treatment are important steps in pre- venting adverse consequences. The risk of malignancy in the undescended testis is 4 to 10 times higher than in the general population. 54 The increased risk of testicular cancer is not significantly affected by orchiopexy, hor- monal therapy, or late spontaneous descent after the age of 2 years. However, orchiopexy does allow for earlier